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Red Hat OpenStack Platform
8
Networking Guide
An Advanced Guide to OpenStack Networking
OpenStack Team
Red Hat OpenStack Platform 8 Networking Guide
An Advanced Guide to OpenStack Networking
OpenStack Team
rhos-docs@redhat.com
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Abstract
A Cookbook for Common OpenStack Networking Tasks.
Table of Contents
Table of Contents
.PREFACE
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5. . . . . . . . . .
1. OPENSTACK NETWORKING AND SDN
5
2. THE POLITICS OF VIRTUAL NETWORKS
5
.CHAPTER
. . . . . . . . .1.. .NETWORKING
. . . . . . . . . . . . .OVERVIEW
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7. . . . . . . . . .
1.1. How Networking Works
7
1.2. Connecting two LANs together
7
1.3. Networking in OpenStack
8
1.4. Advanced OpenStack Networking Concepts
8
.CHAPTER
. . . . . . . . .2.. .OPENSTACK
. . . . . . . . . . . .NETWORKING
. . . . . . . . . . . . .CONCEPTS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
...........
2.1. Installing OpenStack Networking (neutron)
11
2.2. OpenStack Networking diagram
11
2.3. Security Groups
11
2.4. Open vSwitch
12
2.5. Modular Layer 2 (ML2)
12
2.6. Network Back Ends in OpenStack
13
2.7. L2 Population
14
2.8. OpenStack Networking Services
2.9. Tenant and Provider networks
2.10. Layer 2 and layer 3 networking
15
15
19
. . . . . .I.. COMMON
PART
. . . . . . . . . TASKS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
...........
.CHAPTER
. . . . . . . . .3.. .COMMON
. . . . . . . . .ADMINISTRATIVE
. . . . . . . . . . . . . . . .TASKS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
...........
3.1. Create a network
22
3.2. Create an advanced network
24
3.3. Add network routing
3.4. Delete a network
25
25
3.5. Create a subnet
3.6. Delete a subnet
25
27
3.7. Add a router
3.8. Delete a router
27
28
3.9. Add an interface
3.10. Delete an interface
28
28
3.11. Configure IP addressing
3.12. Create multiple floating IP pools
3.13. Bridge the physical network
28
30
30
.CHAPTER
. . . . . . . . .4.. .PLANNING
. . . . . . . . . .IP. .ADDRESS
. . . . . . . . . USAGE
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
...........
4.1. Using multiple VLANs
32
4.2. Isolating VLAN traffic
4.3. IP address consumption
4.4. Virtual Networking
4.5. Example network plan
32
34
34
34
. . . . . . . . . .5.. .REVIEW
CHAPTER
. . . . . . . OPENSTACK
. . . . . . . . . . . . NETWORKING
. . . . . . . . . . . . . ROUTER
. . . . . . . . PORTS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
...........
5.1. View current port status
36
.CHAPTER
. . . . . . . . .6.. .TROUBLESHOOT
. . . . . . . . . . . . . . . PROVIDER
. . . . . . . . . . NETWORKS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
...........
6.1. Topics covered
38
6.2. Basic ping testing
38
6.3. Troubleshooting VLAN networks
40
6.4. Troubleshooting from within tenant networks
41
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6.4. Troubleshooting from within tenant networks
41
.CHAPTER
. . . . . . . . .7.. .CONNECT
. . . . . . . . . AN
. . . INSTANCE
. . . . . . . . . .TO
. . .THE
. . . . PHYSICAL
. . . . . . . . . .NETWORK
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
...........
7.1. Using Flat Provider Networks
44
7.2. Using VLAN provider networks
52
7.3. Enable Compute metadata access
59
7.4. Floating IP addresses
59
.CHAPTER
. . . . . . . . .8.. .CONFIGURE
. . . . . . . . . . . PHYSICAL
. . . . . . . . . .SWITCHES
. . . . . . . . . .FOR
. . . .OPENSTACK
. . . . . . . . . . . .NETWORKING
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
...........
8.1. Planning your physical network environment
60
8.2. Configure a Cisco Catalyst switch
60
8.3. Configure a Cisco Nexus switch
66
8.4. Configure a Cumulus Linux switch
69
8.5. Configure an Extreme Networks EXOS switch
8.6. Configure a Juniper EX Series switch
72
75
. . . . . .II.
PART
. .ADVANCED
. . . . . . . . . . .CONFIGURATION
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80
...........
.CHAPTER
. . . . . . . . .9.. .CONFIGURE
. . . . . . . . . . . MTU
. . . . SETTINGS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81
...........
9.1. MTU overview
81
. . . . . . . . . .10.
CHAPTER
. . .CONFIGURE
. . . . . . . . . . . QUALITY-OF-SERVICE
. . . . . . . . . . . . . . . . . . . . (QOS)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
...........
10.1. QoS Policy Scope
10.2. QoS Policy Management
84
84
. . . . . . . . . .11.
CHAPTER
. . .CONFIGURE
. . . . . . . . . . . BRIDGE
. . . . . . . .MAPPINGS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
...........
11.1. What are bridge mappings used for?
86
11.2. Maintaining Bridge Mappings
87
.CHAPTER
. . . . . . . . .12.
. . .CONFIGURE
. . . . . . . . . . . RBAC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89
...........
12.1. Create a new RBAC policy
89
12.2. Review your configured RBAC policies
12.3. Delete a RBAC policy
90
90
. . . . . . . . . .13.
CHAPTER
. . .CONFIGURE
. . . . . . . . . . . DISTRIBUTED
. . . . . . . . . . . . .VIRTUAL
. . . . . . . .ROUTING
. . . . . . . . .(DVR)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92
...........
13.1. Configure DVR
92
. . . . . . . . . .14.
CHAPTER
. . .CONFIGURE
. . . . . . . . . . . LOAD
. . . . . .BALANCING-AS-A-SERVICE
. . . . . . . . . . . . . . . . . . . . . . . . .(LBAAS)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94
...........
14.1. OpenStack Networking and LBaaS Topology
14.2. Configure LBaaS
95
95
14.3. On the network node (running the LBaaS Agent)
96
. . . . . . . . . .15.
CHAPTER
. . .TENANT
. . . . . . . .NETWORKING
. . . . . . . . . . . . .WITH
. . . . .IPV6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98
...........
15.1. IPv6 subnet options
98
.CHAPTER
. . . . . . . . .16.
. . .MANAGE
. . . . . . . . TENANT
. . . . . . . . QUOTAS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102
............
16.1. L3 quota options
102
16.2. Firewall quota options
16.3. Security group quota options
102
102
16.4. Management quota options
102
. . . . . . . . . .17.
CHAPTER
. . .CONFIGURE
. . . . . . . . . . . FIREWALL-AS-A-SERVICE
. . . . . . . . . . . . . . . . . . . . . . . (FWAAS)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
............
17.1. Enable FWaaS
17.2. Configure FWaaS
103
104
17.3. Create a firewall
104
17.4. Allowed-address-pairs
105
. . . . . . . . . .18.
CHAPTER
. . .CONFIGURE
. . . . . . . . . . . LAYER
. . . . . . .3. HIGH
. . . . . AVAILABILITY
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106
............
2
Table of Contents
18.1. OpenStack Networking without HA
106
18.2. Overview of Layer 3 High Availability
18.3. Tenant considerations
106
108
18.4. Background changes
108
18.5. Configuration Steps
18.6. Configure the OpenStack Networking node
108
108
18.7. Review your configuration
109
.CHAPTER
. . . . . . . . .19.
. . .SR-IOV
. . . . . . SUPPORT
. . . . . . . . . .FOR
. . . .VIRTUAL
. . . . . . . . NETWORKING
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110
............
19.1. Configure SR-IOV in your RHEL OpenStack Platform deployment
110
19.2. Create Virtual Functions on the Compute node
110
19.3. Configure SR-IOV on the Network Node
19.4. Configure SR-IOV on the Controller Node
114
115
19.5. Configure SR-IOV in Compute
115
19.6. Enable the OpenStack Networking SR-IOV agent
19.7. Configure an instance to use the SR-IOV port
116
117
19.8. Review the allow_unsafe_interrupts setting
19.9. Additional considerations
118
119
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4
PREFACE
PREFACE
OpenStack Networking (codename neutron) is the software-defined networking component of Red
Hat OpenStack Platform 8.
1. OPENSTACK NETWORKING AND SDN
Software-defined Networking (SDN) is the term used to describe virtual network functions. While
server workloads have been migrated into virtual environments, they’re still just servers looking for a
network connection to let them send and receive data. SDN meets this need by moving networking
equipment (such as routers and switches) into the same virtualized space. If you’re already familiar
with basic networking concepts, then it’s not much of a leap to consider that they’ve now been
virtualized just like the servers they’re connecting.
This book intends to give administrators an understanding of basic administration and
troubleshooting tasks in Part 1, and also explores the advanced capabilities of OpenStack
Networking in a cookbook style in Part 2. If you’re already comfortable with general networking
concepts, then the content of this book should be accessible to you (someone less familiar with
networking might benefit from the general networking overview in Part 1).
1.1. Topics covered in this book
Preface - Describes the political landscape of SDN in large organizations, and offers a short
introduction to general networking concepts.
Part 1 - Covers common administrative tasks and basic troubleshooting steps:
Adding and removing network resources
Basic network troubleshooting
Tenant network troubleshooting
Part 2 - Contains cookbook-style scenarios for advanced OpenStack Networking features,
including:
Configure Layer 3 High Availability for virtual routers
Configure SR-IOV, and DVR, and other Neutron features
2. THE POLITICS OF VIRTUAL NETWORKS
Software-defined networking (SDN) allows engineers to deploy virtual routers and switches in their
virtualization environment, be it OpenStack or RHEV-based. SDN also shifts the business of moving
data packets between computers into an unfamiliar space. These routers and switches were
previously physical devices with all kinds of cabling running through them, but with SDN they can be
deployed and operational just by clicking a few buttons.
In many large virtualization environments, the adoption of software-defined networking (SDN) can
result in political tensions within the organisation. Virtualization engineers who may not be familiar
with advanced networking concepts are expected to suddenly manage the virtual routers and
switches of their cloud deployment, and need to think sensibly about IP address allocation, VLAN
isolation, and subnetting. And while this is going on, the network engineers are watching this other
team discuss technologies that used to be their exclusive domain, resulting in agitation and perhaps
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Red Hat OpenStack Platform 8 Networking Guide
job security concerns. This demarcation can also greatly complicate troubleshooting: When systems
are down and can’t connect to each other, are the virtualization engineers expected to handover the
troubleshooting efforts to the network engineers the moment they see the packets reaching the
physical switch?
This tension can be more easily mitigated if you think of your virtual network as an extension of your
physical network. All of the same concepts of default gateways, routers, and subnets still apply, and
it all still runs using TCP/IP and VLANs and MAC addresses. Very often the virtual switches will be
expected to trunk the VLANs configured on the physical switches themselves, quite literally making
them an extension of the physical network.
However you choose to manage this politically, there are also technical measures available to
address this. For example, Cisco’s Nexus product enables OpenStack operators to deploy a virtual
router that runs the familiar Cisco NX-OS. This allows network engineers to login and manage
network ports the way they already do with their existing physical Cisco networking equipment.
Alternatively, if the network engineers are not going to manage the virtual network, it would still be
sensible to involve them from the very beginning. Physical networking infrastructure will still be
required for the OpenStack nodes, IP addresses will still need to be allocated, VLANs will need to be
trunked, and switch ports will need to be configured to trunk the VLANs. Aside from troubleshooting,
there are times when extensive co-operation will be expected from both teams. For example, when
adjusting the MTU size for a VM, this will need to be done from end-to-end, including all virtual and
physical switches and routers, requiring a carefully choreographed change between both teams.
Network engineers remain a critical part of your virtualization deployment, even more so after the
introduction of SDN. The additional complexity will certainly need to draw on their skills, especially
when things go wrong and their sage wisdom is needed.
6
CHAPTER 1. NETWORKING OVERVIEW
CHAPTER 1. NETWORKING OVERVIEW
1.1. How Networking Works
The term Networking refers to the act of moving information from one computer to another. At the
most basic level, this is performed by running a cable between two machines, each with network
interface cards (NICs) installed.
Note
If you’ve ever studied the OSI networking model, this would be layer 1.
Now, if you want more than two computers to get involved in the conversation, you would need to
scale out this configuration by adding a device called a switch. Enterprise switches resemble pizza
boxes with multiple ethernet ports for you to plug in additional machines. By the time you’ve done all
this, you have on your hands something that’s called a Local Area Network (LAN).
Switches move us up the OSI model to layer two, and apply a bit more intelligence than the lower
layer 1: Each NIC has a unique MAC address number assigned to the hardware, and it’s this number
that lets machines plugged into the same switch find each other. The switch maintains a list of which
MAC addresses are plugged into which ports, so that when one computer attempts to send data to
another, the switch will know where they’re both situated, and will adjust entries in the Forwarding
Information Base (FIB), which keeps track of MAC-address-to-port mappings.
1.2. Connecting two LANs together
Imagine that you have two LANs running on two separate switches, and now you’d like them to
share information with each other. You have two options to achieve this:
First option: Connect the two switches together using something called a trunk cable. For this to
work, you take a network cable and plug one end into a port on each switch, then you configure
these ports as trunk ports. Basically you’ve now configured these two switches to act as one big
logical switch, and the connected computers can now successfully find each other. The
downside to this option is scalability, you can only daisy-chain so many switches until overhead
becomes an issue.
Second option: Buy a device called a router and plug in cables from each switch. As a result,
the router will be aware of the networks configured on both switches. Each end plugged into the
switch will be assigned an IP address, known as the default gateway for that network. The
"default" in default gateway defines the destination where traffic will be sent if is clear that the
destined machine is not on the same LAN as you. By setting this default gateway on each of
your computers, they don’t need to be aware of all the other computers on the other networks in
order to send traffic to them. Now they just send it on to the default gateway and let the router
handle it from there. And since the router is aware of which networks reside on which interface, it
should have no trouble sending the packets on to their intended destinations. Routing works at
layer 3 of the OSI model, and is where the familiar concepts like IP addresses and subnets do
their work.
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Note
This concept is how the internet itself works. Lots of separate networks run by different
organizations are all interconnected using switches and routers. Keep following the right
default gateways and your traffic will eventually get to where it needs to be.
1.2.1. VLANs
VLANs allow you to segment network traffic for computers running on the same switch. In other
words, you can logically carve up your switch by configuring the ports to be members of different
networks — they are basically mini-LANs that allow you to separate traffic for security reasons. For
example, if your switch has 24 ports in total, you can say that ports 1-6 belong to VLAN200, and
ports 7-18 belong to VLAN201. As a result, computers plugged into VLAN200 are completely
separate from those on VLAN201; they can no longer communicate directly, and if they wanted to,
the traffic would have to pass through a router as if they were two separate physical switches (which
would be a useful way to think of them). This is where firewalls can also be useful for governing
which VLANs can communicate with each other:
1.2.2. Firewalls
Firewalls operate at the same OSI layer as IP routing, but also work at layer 4 when managing traffic
based on TCP/UDP port numbers. They are often situated in the same network segments as
routers, where they govern the traffic moving between all the networks. Firewalls refer to a predefined set of rules that prescribe which traffic may or may not enter a network. These rules can
become very granular, for example:
"Servers on VLAN200 may only communicate with computers on VLAN201, and only on a Thursday
afternoon, and only if they are sending encrypted web traffic (HTTPS) in one direction".
To help enforce these rules, some firewalls also perform Deep Packet Inspection (DPI) at layers 57, whereby they examine the contents of packets to ensure they actually are whatever they claim to
be. Hackers are known to exfiltrate data by having the traffic masquerade as something it’s not, so
DPI is one of the means that can help mitigate that threat.
1.3. Networking in OpenStack
These same concepts apply in OpenStack, where they are known as Software-Defined Networking
(SDN). Virtual switches (using Open vSwitch) and routers (l3-agent) allow your instances to
communicate with each other; they can also communicate externally using the physical network.
The Open vSwitch bridge allocates virtual ports to instances, and can span across to the physical
network for incoming and outgoing traffic.
1.4. Advanced OpenStack Networking Concepts
1.4.1. Layer 3 High Availability
OpenStack Networking hosts virtual routers on a centralised Network node, which is a physical
server dedicated to the function of hosting the virtual networking components. These virtual routers
direct traffic to and from virtual machines, and so are vital to the continued connectivity of your
environment. Since physical servers can (will) go offline for many reasons, this leaves your virtual
machines vulnerable to outages when the Network node goes offline.
8
CHAPTER 1. NETWORKING OVERVIEW
OpenStack Networking uses Layer 3 High Availability to help mitigate this risk, implementing the
industry standard VRRP protocol to protect virtual routers and floating IP addresses. With Layer 3
High Availability, a tenant’s virtual routers are randomly allocated across multiple physical Network
nodes, with one router designated as the active router, and the remainder serving in a standby role,
ready to take over if the Network node hosting the active router goes offline.
Note
The "Layer 3" refers to the section of the OSI model where this feature functions, meaning
that it assists with protecting routing and IP addressing.
For more information, refer to the chapter "Configure Layer 3 High Availability".
1.4.2. HAproxy
HAProxy is the built-in load balancer (distinct from LBaaS) that distributes connections between all
available controllers, as part of the High Availability (HA) solution. HAProxy operates at layer 4,
since it is based on the UDP/TCP port numbers assigned to each service. VRRP determines which
HAProxy instance connections are initially sent to, then HAProxy distributes the connections to the
servers on the back end. This configuration can be considered high availability load balancing, as
opposed to LBaaS, which is described next.
1.4.3. Load Balancing-as-a-Service (LBaaS)
Load Balancing-as-a-Service (LBaaS) enables OpenStack Networking to distribute incoming
network requests evenly between designated instances. This ensures the workload is shared
predictably among instances, and allows more effective use of system resources. Incoming
requests are distributed using one of these load balancing methods:
Round robin - Rotates requests evenly between multiple instances.
Source IP - Requests from a unique source IP address are consistently directed to the same
instance.
Least connections - Allocates requests to the instance with the least number of active
connections.
For more information, refer to the chapter: "Configure Load Balancing-as-a-Service (LBaaS)".
1.4.4. IPv6
OpenStack Networking includes support for IPv6 in tenant networks, meaning that you can
dynamically assign IPv6 addresses to virtual machines. OpenStack Networking is also able to
integrate with SLAAC on your physical routers, so that virtual machines can receive IPv6 addresses
from your existing DHCP infrastructure.
For more information, refer to the chapter "Tenant Networking with IPv6".
1.4.5. Using CIDR format
IP addresses are generally first allocated in blocks of subnets. For example, the IP address range
192.168.100.0 - 192.168.100.255 with a subnet mask of 255.555.255.0 allows for 254
IP addresses (the first and last addresses are reserved).
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Red Hat OpenStack Platform 8 Networking Guide
These subnets can be represented in a number of ways:
Common usage: Subnet addresses are traditionally displayed using the network address
accompanied by the subnet mask. For example:
Network Address: 192.168.100.0
Subnet mask: 255.255.255.0
Using CIDR format: This format shortens the subnet mask into its total number of active bits. For
example, in 192.168.100.0/24 the /24 is a shortened representation of 255.255.255.0,
and is a total of the number of flipped bits when converted to binary. For example, CIDR format
can be used in ifcfg-xxx scripts instead of the NETMASK value:
#NETMASK=255.255.255.0
PREFIX=24
10
CHAPTER 2. OPENSTACK NETWORKING CONCEPTS
CHAPTER 2. OPENSTACK NETWORKING CONCEPTS
OpenStack Networking has system services to manage core services such routing, DHCP, and
metadata. Together, these services make up the concept of the Network node, which is a conceptual
role assigned to a physical server. A physical server is typically assigned the role of Network node,
keeping it dedicated to the task of managing Layer 3 routing for network traffic to and from
instances. In OpenStack Networking, you can have multiple physical hosts performing this role,
allowing for redundant service in the event of hardware failure. For more information, see the
chapter on Layer 3 High Availability.
2.1. Installing OpenStack Networking (neutron)
2.1.1. Supported installation
In Red Hat OpenStack Platform 8 (liberty), the OpenStack Networking component is installed as part
of a RHEL OpenStack director deployment. Refer to the RHEL OpenStack director installation guide
for more information.
2.2. OpenStack Networking diagram
This diagram depicts a sample OpenStack Networking deployment, with a dedicated OpenStack
Networking node performing L3 routing and DHCP, and running the advanced services FWaaS and
LBaaS. Two Compute nodes run the Open vSwitch (ovs-agent) and have two physical network
cards each, one for tenant traffic, and another for management connectivity. The OpenStack
Networking node has a third network card specifically for provider traffic:
2.3. Security Groups
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Security groups and rules filter the type and direction of network traffic sent to a given neutron port.
This provides an additional layer of security to complement any firewall rules present on the
Compute instance. The security group is a container object with one or more security rules. A single
security group can manage traffic to multiple compute instances. Ports created for floating IP
addresses, OpenStack Networking LBaaS VIPs, router interfaces, and instances are associated
with a security group. If none is specified, then the port is associated with the default security group.
By default, this group will drop all inbound traffic and allow all outbound traffic. Additional security
rules can be added to the default security group to modify its behavior or new security groups can
be created as necessary. The Open vSwitch, Linux Bridge, VMware NSX, NEC, and Ryu networking
plug-ins currently support security groups.
Note
Unlike Compute security groups, OpenStack Networking security groups are applied on a
per port basis rather than on a per instance basis.
2.4. Open vSwitch
Open vSwitch (OVS) is a software-defined networking (SDN) virtual switch that replaces the Linux
software bridge. OVS provides switching services to virtualized networks with support for industry
standard NetFlow, OpenFlow, and sFlow. Open vSwitch is also able to integrate with physical
switches using the layer 2 features STP, LACP, and 802.1Q VLAN tagging. Open vSwitch tunneling
is supported with Open vSwitch version 1.11.0-1.el6 or later. Refer to the table below for specific
kernel requirements:
Note
Do not use LACP with OVS-based bonds, as this configuration is problematic and
unsupported. Instead, consider using bond_mode=balance-slb as a replacement for
this functionality. In addition, you can still use LACP with Linux bonding.
2.5. Modular Layer 2 (ML2)
ML2 is the new OpenStack Networking core plug-in introduced in OpenStack’s Havana release.
Superseding the previous model of singular plug-ins, ML2’s modular design enables the concurrent
operation of mixed network technologies. The monolithic Open vSwitch and linuxbridge plug-ins
have been deprecated and will be removed in a future release; their functionality has instead been
reimplemented as ML2 mechanisms.
Note
ML2 is the default OpenStack Networking plug-in, with Open vSwitch configured as the
default mechanism driver.
2.5.1. The reasoning behind ML2
Previously, OpenStack Networking deployments were only able to use the plug-in that had been
selected at implementation time. For example, a deployment running the Open vSwitch plug-in was
only able to use Open vSwitch exclusively; it wasn’t possible to simultaneously run another plug-in
such as linuxbridge. This was found to be a limitation in environments with heterogeneous
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CHAPTER 2. OPENSTACK NETWORKING CONCEPTS
requirements.
2.5.2. ML2 network types
Multiple network segment types can be operated concurrently. In addition, these network segments
can interconnect using ML2’s support for multi-segmented networks. Ports are automatically bound
to the segment with connectivity; it is not necessary to bind them to a specific segment. Depending
on the mechanism driver, ML2 supports the following network segment types: * flat * GRE * local *
VLAN * VXLAN
The various Type drivers are enabled in the ML2 section of the ml2_conf.ini file:
[ml2]
type_drivers = local,flat,vlan,gre,vxlan
2.5.3. ML2 Mechanisms
Plug-ins have been reimplemented as mechanisms with a common code base. This approach
enables code reuse and eliminates much of the complexity around code maintenance and testing.
Note
Refer to the Release Notes for the list of supported mechanism drivers.
The various mechanism drivers are enabled in the ML2 section of the ml2_conf.ini file. For
example:
[ml2]
mechanism_drivers = openvswitch,linuxbridge,l2population
Note
If your deployment uses Red Hat OpenStack Platform director, then these settings are
managed by puppet and should not be changed manually.
2.6. Network Back Ends in OpenStack
The Red Hat OpenStack Platform offers two distinctly different networking back ends: Nova
networking and OpenStack Networking (neutron). Nova networking has been deprecated in the
OpenStack technology roadmap, but still remains currently available. OpenStack Networking is
considered the core software-defined networking (SDN) component of OpenStack’s forward-looking
roadmap and is under active development. It is important to consider that there is currently no
migration path between Nova networking and OpenStack Networking. This would impact an
operator’s plan to deploy Nova networking with the intention of upgrading to OpenStack Networking
at a later date. At present, any attempt to switch between these technologies would need to be
performed manually, and would likely require planned outages.
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Note
Nova networking is not available for deployment using the Red Hat OpenStack Platform
Director.
2.6.1. Choose OpenStack Networking (neutron)
If you require an overlay network solution: OpenStack Networking supports GRE or VXLAN
tunneling for virtual machine traffic isolation. With GRE or VXLAN, no VLAN configuration is
required on the network fabric and the only requirement from the physical network is to provide
IP connectivity between the nodes. Furthermore, VXLAN or GRE allows a theoretical scale limit
of 16 million unique IDs which is far beyond the 4094 limitation of 802.1q VLAN ID. Nova
networking bases the network segregation on 802.1q VLANs and does not support tunneling
with GRE or VXLAN.
If you require overlapping IP addresses between tenants: OpenStack Networking uses the
network namespace capabilities in the Linux kernel, which allows different tenants to use the
same subnet range (e.g. 192.168.1/24) on the same Compute node without any risk of overlap
or interference. This is suited for large multi-tenancy deployments. By comparison, Nova
networking offers flat topologies that must remain mindful of subnets used by all tenants.
If you require a Red Hat-certified third-party OpenStack Networking plug-in: By default, Red Hat
OpenStack Platform 8 uses the open source ML2 core plug-in with the Open vSwitch (OVS)
mechanism driver. Based on the physical network fabric and other network requirements, thirdparty OpenStack Networking plug-ins can be deployed instead of the default ML2/Open vSwitch
driver due to the pluggable architecture of OpenStack Networking. Red Hat is constantly working
to enhance our Partner Certification Program to certify more OpenStack Networking plugins
against Red Hat OpenStack Platform. You can learn more about our Certification Program and
the certified OpenStack Networking plug-ins at http://marketplace.redhat.com.
If you require Firewall-as-a-service (FWaaS) or Load-Balancing-as-a-service (LBaaS): These
network services are only available in OpenStack Networking and are not available for Nova
networking. The dashboard allows tenants to manage these services with no need for
administrator intervention.
2.6.2. Choose Nova Networking
If your deployment requires flat (untagged) or VLAN (802.1q tagged) networking: This implies
scalabilty requirements (theoretical scale limit of 4094 VLAN IDs, where in practice physical
switches tend to support a much lower number) as well as management and provisioning
requirements. Specific configuration is necessary on the physical network to trunk the required
set of VLANs between the nodes.
If your deployment does not require overlapping IP addresses between tenants: This is usually
suitable only for small, private deployments.
If you do not need a software-defined networking (SDN) solution, or the ability to interact with the
physical network fabric.
If you do not need self-service VPN, Firewall, or Load-Balancing services.
2.7. L2 Population
The L2 Population driver enables broadcast, multicast, and unicast traffic to scale out on large
overlay networks. By default, Open vSwitch GRE and VXLAN replicate broadcasts to every agent,
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CHAPTER 2. OPENSTACK NETWORKING CONCEPTS
including those that do not host the destination network. This design requires the acceptance of
significant network and processing overhead. The alternative design introduced by the L2
Population driver implements a partial mesh for ARP resolution and MAC learning traffic. This traffic
is sent only to the necessary agent by encapsulating it as a targeted unicast. Enable the L2
population driver by adding it to the list of mechanism drivers. You also need to have at least one
tunneling driver enabled; either GRE, VXLAN, or both. Add the appropriate configuration options to
the ml2_conf.ini file:
[ml2]
type_drivers = local,flat,vlan,gre,vxlan
mechanism_drivers = openvswitch,linuxbridge,l2population
Enable L2 population in the ovs_neutron_plugin.ini file. This must be enabled on each node running
the L2 agent:
[agent]
l2_population = True
2.8. OpenStack Networking Services
OpenStack Networking integrates with a number of components to provide networking functionality
in your deployment:
2.8.1. L3 Agent
The L3 agent is part of the openstack-neutron package. It acts as a virtual layer 3 router that directs
traffic and provides gateway services for layer 2 networks. The nodes on which the L3 agent is to be
hosted must not have a manually-configured IP address on a network interface that is connected to
an external network. Instead there must be a range of IP addresses from the external network that
are available for use by OpenStack Networking. These IP addresses will be assigned to the routers
that provide the link between the internal and external networks. The range selected must be large
enough to provide a unique IP address for each router in the deployment as well as each desired
floating IP.
DHCP Agent - The OpenStack Networking DHCP agent is capable of allocating IP addresses to
virtual machines running on the network. If the agent is enabled and running when a subnet is
created then by default that subnet has DHCP enabled.
Plug-in Agent - Many Networking plug-ins will utilize their own agent, including Open vSwitch
and Linux Bridge. The plug-in specific agent runs on each node that manages network traffic.
This includes all compute nodes, as well as nodes running the dedicated agents neutron-dhcpagent and neutron-l3-agent.
2.9. Tenant and Provider networks
The following diagram presents an overview of the tenant and provider network types, and illustrates
how they interact within the overall OpenStack Networking topology:
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2.9.1. Tenant networks
Tenant networks are created by users for connectivity within projects; they are fully isolated by
default and are not shared with other projects. OpenStack Networking supports a range of tenant
network types:
Flat - All instances reside on the same network, which can also be shared with the hosts. No
VLAN tagging or other network segregation takes place.
VLAN - OpenStack Networking allows users to create multiple provider or tenant networks using
VLAN IDs (802.1Q tagged) that correspond to VLANs present in the physical network. This
allows instances to communicate with each other across the environment. They can also
communicate with dedicated servers, firewalls, load balancers and other network infrastructure
on the same layer 2 VLAN.
Note
You can also configure QoS policies for tenant networks. For more information, see
Chapter 10, Configure Quality-of-Service (QoS).
2.9.2. VXLAN and GRE tunnels
VXLAN and GRE use network overlays to support private communication between instances. An
OpenStack Networking router is required to enable traffic to traverse outside of the GRE or VXLAN
tenant network. A router is also required to connect directly-connected tenant networks with
external networks, including the Internet; the router provides the ability to connect to instances
directly from an external network using floating IP addresses.
2.9.3. Provider networks
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CHAPTER 2. OPENSTACK NETWORKING CONCEPTS
2.9.3. Provider networks
Provider networks are created by the OpenStack administrator and map directly to an existing
physical network in the data center. Useful network types in this category are flat (untagged) and
VLAN (802.1Q tagged). It is possible to allow provider networks to be shared among tenants as part
of the network creation process.
2.9.3.1. Flat provider networks
You can use flat provider networks to connect instances directly to the external network. This is
useful if you have multiple physical networks (for example, physnet1 and physnet2) and separate
physical interfaces (eth0 - > physnet1 and eth1 → physnet2), and intend to connect each Compute
and Network node to those external networks. If you would like to use multiple vlan-tagged
interfaces on a single interface to connect to multiple provider networks, please refer to Section 7.2,
“Using VLAN provider networks”.
2.9.3.2. Configure controller nodes
1. Edit /etc/neutron/plugin.ini (symbolic link to /etc/neutron/plugins/ml2/ml2_conf.ini) and add flat to
the existing list of values, and set flat_networks to *. For example:
type_drivers = vxlan,flat
flat_networks =*
2. Create an external network as a flat network and associate it with the configured
physical_network. Configuring it as a shared network (using --shared) will allow other users to
create instances directly to it.
neutron net-create public01 --provider:network_type flat -provider:physical_network physnet1 --router:external=True --shared
3. Create a subnet using neutron subnet-create, or the dashboard. For example:
# neutron subnet-create --name public_subnet --enable_dhcp=False -allocation_pool start=192.168.100.20,end=192.168.100.100 -gateway=192.168.100.1 public 192.168.100.0/24
4. Restart the neutron-server service to apply the change:
systemctl restart neutron-server
2.9.3.3. Configure the Network and Compute nodes
Perform these steps on the network node and compute nodes. This will connect the nodes to the
external network, and allow instances to communicate directly with the external network.
1. Create an external network bridge (br-ex) and add an associated port (eth1) to it:
Create the external bridge in /etc/sysconfig/network-scripts/ifcfg-br-ex:
DEVICE=br-ex
TYPE=OVSBridge
DEVICETYPE=ovs
ONBOOT=yes
NM_CONTROLLED=no
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BOOTPROTO=none
In /etc/sysconfig/network-scripts/ifcfg-eth1, configure eth1 to connect to br-ex:
DEVICE=eth1
TYPE=OVSPort
DEVICETYPE=ovs
OVS_BRIDGE=br-ex
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=none
Reboot the node or restart the network service for the changes to take effect.
2. Configure physical networks in /etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini and map
bridges to the physical network:
bridge_mappings = physnet1:br-ex
Note
For more information on bridge mappings, see Chapter 11, Configure Bridge Mappings.
3. Restart the neutron-openvswitch-agent service on both the network and compute nodes for the
changes to take effect:
systemctl restart neutron-openvswitch-agent
2.9.3.4. Configure the network node
1. Set external_network_bridge = to an empty value in /etc/neutron/l3_agent.ini:
Previously, OpenStack Networking used external_network_bridge when only a single bridge
was used for connecting to an external network. This value may now be set to a blank string, which
allows multiple external network bridges. OpenStack Networking will then create a patch from each
bridge to br-int.
# Name of bridge used for external network traffic. This should be set
to
# empty value for the linux bridge
external_network_bridge =
2. Restart neutron-l3-agent for the changes to take effect.
systemctl restart neutron-l3-agent
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CHAPTER 2. OPENSTACK NETWORKING CONCEPTS
Note
If there are multiple flat provider networks, then each of them should have a separate
physical interface and bridge to connect them to the external network. You will need to
configure the ifcfg-* scripts appropriately and use a comma-separated list for each
network when specifying the mappings in the bridge_mappings option. For more
information on bridge mappings, see Chapter 11, Configure Bridge Mappings.
2.10. Layer 2 and layer 3 networking
When designing your virtual network, you will need to anticipate where the majority of traffic is going
to be sent. Network traffic moves faster within the same logical network, rather than between
networks. This is because traffic between logical networks (using different subnets) needs pass
through a router, resulting in additional latency.
Consider the diagram below which has network traffic flowing between instances on separate
VLANs:
Note
Even a high performance hardware router is still going to add some latency to this
configuration.
2.10.1. Use switching where possible
Switching occurs at a lower level of the network (layer 2), so can function much quicker than the
routing that occurs at layer 3. The preference should be to have as few hops as possible between
systems that frequently communicate. For example, this diagram depicts a switched network that
spans two physical nodes, allowing the two instances to directly communicate without using a router
for navigation first. You’ll notice that the instances now share the same subnet, to indicate that
they’re on the same logical network:
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In order to allow instances on separate nodes to communicate as if they’re on the same logical
network, you’ll need to use an encapsulation tunnel such as VXLAN or GRE. It is recommended you
consider adjusting the MTU size from end-to-end in order to accommodate the additional bits
required for the tunnel header, otherwise network performance can be negatively impacted as a
result of fragmentation. You can further improve the performance of VXLAN tunneling by using
supported hardware that features VXLAN offload capabilities. The full list is available here:
https://access.redhat.com/articles/1390483
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PART I. COMMON TASKS
PART I. COMMON TASKS
Covers common administrative tasks and basic troubleshooting steps.
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CHAPTER 3. COMMON ADMINISTRATIVE TASKS
OpenStack Networking (neutron) is the software-defined networking component of Red Hat
OpenStack Platform. The virtual network infrastructure enables connectivity between instances and
the physical external network.
This section describes common administration tasks, such as adding and removing subnets and
routers to suit your Red Hat OpenStack Platform deployment.
3.1. Create a network
Create a network to give your instances a place to communicate with each other and receive IP
addresses using DHCP. A network can also be integrated with external networks in your Red Hat
OpenStack Platform deployment or elsewhere, such as the physical network. This integration allows
your instances to communicate with, and be reachable by, outside systems. To integrate your
network with your physical external network, see section: “Bridge the physical network”.
When creating networks, it is important to know that networks can host multiple subnets. This is
useful if you intend to host distinctly different systems in the same network, and would prefer a
measure of isolation between them. For example, you can designate that only webserver traffic is
present on one subnet, while database traffic traverse another. Subnets are isolated from each
other, and any instance that wishes to communicate with another subnet must have their traffic
directed by a router. Consider placing systems that will require a high volume of traffic amongst
themselves in the same subnet, so that they don’t require routing, and avoid the subsequent latency
and load.
1. In the dashboard, select Project > Network > Networks.
2. Click +Create Network and specify the following:
Field
Description
Network Name
Descriptive name, based on the role that the
network will perform. If you are integrating the
network with an external VLAN, consider
appending the VLAN ID number to the name.
Examples: * webservers_122, if you are hosting
HTTP web servers in this subnet, and your VLAN
tag is 122. * internal-only, if you intend to keep the
network traffic private, and not integrate it with an
external network.
Admin State
Controls whether the network is immediately
available. This field allows you to create the
network but still keep it in a Down state, where it is
logically present but still inactive. This is useful if
you do not intend to enter the network into
production right away.
3. Click the Next button, and specify the following in the Subnet tab:
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CHAPTER 3. COMMON ADMINISTRATIVE TASKS
Field
Description
Create Subnet
Determines whether a subnet is created. For
example, you might not want to create a subnet if
you intend to keep this network as a placeholder
without network connectivity.
Subnet Name
Enter a descriptive name for the subnet.
Network Address
Enter the address in CIDR format, which contains
the IP address range and subnet mask in one
value. To determine the address, calculate the
number of bits masked in the subnet mask and
append that value to the IP address range. For
example, the subnet mask 255.255.255.0 has 24
masked bits. To use this mask with the IPv4
address range 192.168.122.0, specify the address
192.168.122.0/24.
IP Version
Specifies the internet protocol, where valid types
are IPv4 or IPv6. The IP address range in the
Network Address field must match whichever
version you select.
Gateway IP
IP address of the router interface for your default
gateway. This address is the next hop for routing
any traffic destined for an external location, and
must be within the range specified in the Network
Address field. For example, if your CIDR network
address is 192.168.122.0/24, then your default
gateway is likely to be 192.168.122.1.
Disable Gateway
Disables forwarding and keeps the network
isolated.
4. Click Next to specify DHCP options:
Enable DHCP - Enables DHCP services for this subnet. DHCP allows you to automate the
distribution of IP settings to your instances.
IPv6 Address -Configuration Modes If creating an IPv6 network, specifies how IPv6 addresses
and additional information are allocated:
No Options Specified - Select this option if IP addresses are set manually, or a non
OpenStack-aware method is used for address allocation.
SLAAC (Stateless Address Autoconfiguration) - Instances generate IPv6 addresses
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based on Router Advertisement (RA) messages sent from the OpenStack Networking router.
This configuration results in an OpenStack Networking subnet created with ra_mode set to
slaac and address_mode set to slaac.
DHCPv6 stateful - Instances receive IPv6 addresses as well as additional options (for
example, DNS) from OpenStack Networking DHCPv6 service. This configuration results in a
subnet created with ra_mode set to dhcpv6-stateful and address_mode set to dhcpv6stateful.
DHCPv6 stateless - Instances generate IPv6 addresses based on Router Advertisement
(RA) messages sent from the OpenStack Networking router. Additional options (for example,
DNS) are allocated from the OpenStack Networking DHCPv6 service. This configuration
results in a subnet created with ra_mode set to dhcpv6-stateless and address_mode set to
dhcpv6-stateless.
Allocation Pools - Range of IP addresses you would like DHCP to assign. For example, the
value 192.168.22.100,192.168.22.100 considers all up addresses in that range as available for
allocation.
DNS Name Servers - IP addresses of the DNS servers available on the network. DHCP
distributes these addresses to the instances for name resolution.
Host Routes - Static host routes. First specify the destination network in CIDR format, followed
by the next hop that should be used for routing. For example: 192.168.23.0/24, 10.1.31.1
Provide this value if you need to distribute static routes to instances.
5. Click Create.
The completed network is available for viewing in the Networks tab. You can also click Edit to
change any options as needed. Now when you create instances, you can configure them now to
use its subnet, and they will subsequently receive any specified DHCP options.
3.2. Create an advanced network
Advanced network options are available for administrators, when creating a network from the Admin
view. These options define the network type to use, and allow tenants to be specified:
1. In the dashboard, select Admin > Networks > Create Network > Project. Select a destination
project to host the new network using Project.
2. Review the options in Provider Network Type:
Local - Traffic remains on the local Compute host and is effectively isolated from any external
networks.
Flat - Traffic remains on a single network and can also be shared with the host. No VLAN
tagging or other network segregation takes place.
VLAN - Create a network using a VLAN ID that corresponds to a VLAN present in the physical
network. Allows instances to communicate with systems on the same layer 2 VLAN.
GRE - Use a network overlay that spans multiple nodes for private communication between
instances. Traffic egressing the overlay must be routed.
VXLAN - Similiar to GRE, and uses a network overlay to span multiple nodes for private
communication between instances. Traffic egressing the overlay must be routed.
Click Create Network, and review the Project’s Network Topology to validate that the network has
been successfully created.
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CHAPTER 3. COMMON ADMINISTRATIVE TASKS
3.3. Add network routing
To allow traffic to be routed to and from your new network, you must add its subnet as an interface
to an existing virtual router:
1. In the dashboard, select Project > Network > Routers.
2. Click on your virtual router’s name in the Routers list, and click +Add Interface. In the Subnet
list, select the name of your new subnet. You can optionally specify an IP address for the interface in
this field.
3. Click Add Interface.
Instances on your network are now able to communicate with systems outside the subnet.
3.4. Delete a network
There are occasions where it becomes necessary to delete a network that was previously created,
perhaps as housekeeping or as part of a decommissioning process. In order to successfully delete a
network, you must first remove or detach any interfaces where it is still in use. The following
procedure provides the steps for deleting a network in your project, together with any dependent
interfaces.
1. In the dashboard, select Project > Network > Networks. Remove all router interfaces associated
with the target network’s subnets. To remove an interface: Find the ID number of the network you
would like to delete by clicking on your target network in the Networks list, and looking at the its ID
field. All the network’s associated subnets will share this value in their Network ID field.
2. Select Project > Network > Routers, click on your virtual router’s name in the Routers list, and
locate the interface attached to the subnet you would like to delete. You can distinguish it from the
others by the IP address that would have served as the gateway IP. In addition, you can further
validate the distinction by ensuring that the interface’s network ID matches the ID you noted in the
previous step.
3. Click the interface’s Delete Interface button.
Select Project > Network > Networks, and click the name of your network. Click the target subnet’s
Delete Subnet button.
Note
If you are still unable to remove the subnet at this point, ensure it is not already being
used by any instances.
Select Project > Network > Networks, and select the network you would like to delete. Click
Delete Networks when prompted, and again in the next confirmation screen.
3.5. Create a subnet
Subnets are the means by which instances are granted network connectivity. Each instance is
assigned to a subnet as part of the instance creation process, therefore it’s important to consider
proper placement of instances to best accommodate their connectivity requirements. Subnets are
created in pre-existing networks. Remember that tenant networks in OpenStack Networking can
host multiple subnets. This is useful if you intend to host distinctly different systems in the same
network, and would prefer a measure of isolation between them. For example, you can designate
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that only webserver traffic is present on one subnet, while database traffic traverse another. Subnets
are isolated from each other, and any instance that wishes to communicate with another subnet
must have their traffic directed by a router. Consider placing systems that will require a high volume
of traffic amongst themselves in the same subnet, so that they don’t require routing, and avoid the
subsequent latency and load.
3.5.1. Create a new subnet
In the dashboard, select Project > Network > Networks, and click your network’s name in the
Networks view.
1. Click Create Subnet, and specify the following.
Field
Description
Subnet Name
Descriptive subnet name.
Network Address
Address in CIDR format, which contains the IP
address range and subnet mask in one value. To
determine the address, calculate the number of bits
masked in the subnet mask and append that value
to the IP address range. For example, the subnet
mask 255.255.255.0 has 24 masked bits. To use
this mask with the IPv4 address range
192.168.122.0, specify the address
192.168.122.0/24.
IP Version
Internet protocol, where valid types are IPv4 or
IPv6. The IP address range in the Network Address
field must match whichever version you select.
Gateway IP
IP address of the router interface for your default
gateway. This address is the next hop for routing
any traffic destined for an external location, and
must be within the range specified in the Network
Address field. For example, if your CIDR network
address is 192.168.122.0/24, then your default
gateway is likely to be 192.168.122.1.
Disable Gateway
Disables forwarding and keeps the network
isolated.
2. Click Next to specify DHCP options:
Enable DHCP - Enables DHCP services for this subnet. DHCP allows you to automate the
distribution of IP settings to your instances.
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CHAPTER 3. COMMON ADMINISTRATIVE TASKS
IPv6 Address -Configuration Modes If creating an IPv6 network, specifies how IPv6 addresses
and additional information are allocated:
No Options Specified - Select this option if IP addresses are set manually, or a non
OpenStack-aware method is used for address allocation.
SLAAC (Stateless Address Autoconfiguration) - Instances generate IPv6 addresses
based on Router Advertisement (RA) messages sent from the OpenStack Networking router.
This configuration results in an OpenStack Networking subnet created with ra_mode set to
slaac and address_mode set to slaac.
DHCPv6 stateful - Instances receive IPv6 addresses as well as additional options (for
example, DNS) from OpenStack Networking DHCPv6 service. This configuration results in a
subnet created with ra_mode set to dhcpv6-stateful and address_mode set to dhcpv6stateful.
DHCPv6 stateless - Instances generate IPv6 addresses based on Router Advertisement
(RA) messages sent from the OpenStack Networking router. Additional options (for example,
DNS) are allocated from the OpenStack Networking DHCPv6 service. This configuration
results in a subnet created with ra_mode set to dhcpv6-stateless and address_mode set to
dhcpv6-stateless.
Allocation Pools - Range of IP addresses you would like DHCP to assign. For example, the
value 192.168.22.100,192.168.22.100 considers all up addresses in that range as available for
allocation.
DNS Name Servers - IP addresses of the DNS servers available on the network. DHCP
distributes these addresses to the instances for name resolution.
Host Routes - Static host routes. First specify the destination network in CIDR format, followed
by the next hop that should be used for routing. For example: 192.168.23.0/24, 10.1.31.1
Provide this value if you need to distribute static routes to instances.
3. Click Create.
The new subnet is available for viewing in your network’s Subnets list. You can also click Edit to
change any options as needed. When you create instances, you can configure them now to use this
subnet, and they will subsequently receive any specified DHCP options.
3.6. Delete a subnet
You can delete a subnet if it is no longer in use. However, if any instances are still configured to use
the subnet, the deletion attempt fails and the dashboard displays an error message. This procedure
demonstrates how to delete a specific subnet in a network:
In the dashboard, select Project > Network > Networks, and click the name of your network. Select
the target subnet and click Delete Subnets.
3.7. Add a router
OpenStack Networking provides routing services using an SDN-based virtual router. Routers are a
requirement for your instances to communicate with external subnets, including those out in the
physical network. Routers and subnets connect using interfaces, with each subnet requiring its own
interface to the router. A router’s default gateway defines the next hop for any traffic received by the
router. Its network is typically configured to route traffic to the external physical network using a
virtual bridge.
1. In the dashboard, select Project > Network > Routers, and click +Create Router.
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Red Hat OpenStack Platform 8 Networking Guide
2. Enter a descriptive name for the new router, and click Create router.
3. Click Set Gateway next to the new router’s entry in the Routers list.
4. In the External Network list, specify the network that will receive traffic destined for an external
location.
5. Click Set Gateway. After adding a router, the next step is to configure any subnets you have
created to send traffic using this router. You do this by creating interfaces between the subnet and
the router.
3.8. Delete a router
You can delete a router if it has no connected interfaces. This procedure describes the steps
needed to first remove a router’s interfaces, and then the router itself.
1. In the dashboard, select Project > Network > Routers, and click on the name of the router you
would like to delete.
2. Select the interfaces of type Internal Interface. Click Delete Interfaces.
3. From the Routers list, select the target router and click Delete Routers.
3.9. Add an interface
Interfaces allow you to interconnect routers with subnets. As a result, the router can direct any traffic
that instances send to destinations outside of their intermediate subnet. This procedure adds a
router interface and connects it to a subnet. The procedure uses the Network Topology feature,
which displays a graphical representation of all your virtual router and networks and enables you to
perform network management tasks.
1. In the dashboard, select Project > Network > Network Topology.
2. Locate the router you wish to manage, hover your mouse over it, and click Add Interface.
3. Specify the Subnet to which you would like to connect the router. You have the option of
specifying an IP Address. The address is useful for testing and troubleshooting purposes, since a
successful ping to this interface indicates that the traffic is routing as expected.
4. Click Add interface.
The Network Topology diagram automatically updates to reflect the new interface connection
between the router and subnet.
3.10. Delete an interface
You can remove an interface to a subnet if you no longer require the router to direct its traffic. This
procedure demonstrates the steps required for deleting an interface:
1. In the dashboard, select Project > Network > Routers.
2. Click on the name of the router that hosts the interface you would like to delete.
3. Select the interface (will be of type Internal Interface), and click Delete Interfaces.
3.11. Configure IP addressing
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CHAPTER 3. COMMON ADMINISTRATIVE TASKS
You can use procedures in this section to manage your IP address allocation in OpenStack
Networking.
3.11.1. Create floating IP pools
Floating IP addresses allow you to direct ingress network traffic to your OpenStack instances. You
begin by defining a pool of validly routable external IP addresses, which can then be dynamically
assigned to an instance. OpenStack Networking then knows to route all incoming traffic destined for
that floating IP to the instance to which it has been assigned.
Note
OpenStack Networking allocates floating IP addresses to all projects (tenants) from the
same IP ranges/CIDRs. Meaning that every subnet of floating IPs is consumable by any
and all projects. You can manage this behavior using quotas for specific projects. For
example, you can set the default to 10 for ProjectA and ProjectB, while setting ProjectC's
quota to 0.
The Floating IP allocation pool is defined when you create an external subnet. If the subnet only
hosts floating IP addresses, consider disabling DHCP allocation with the enable_dhcp=False option:
# neutron subnet-create --name SUBNET_NAME --enable_dhcp=False -allocation_pool start=IP_ADDRESS,end=IP_ADDRESS --gateway=IP_ADDRESS
NETWORK_NAME CIDR
For example:
# neutron subnet-create --name public_subnet --enable_dhcp=False -allocation_pool start=192.168.100.20,end=192.168.100.100 -gateway=192.168.100.1 public 192.168.100.0/24
3.11.2. Assign a specific floating IP
You can assign a specific floating IP address to an instance using the nova command (or through
the dashboard; see Section 3.1.2, “Update an Instance (Actions menu)”).
# nova floating-ip-associate INSTANCE_NAME IP_ADDRESS
In this example, a floating IP address is allocated to an instance named corp-vm-01:
# nova floating-ip-associate corp-vm-01 192.168.100.20
3.11.3. Assign a random floating IP
Floating IP addresses can be dynamically allocated to instances. You do not select a particular IP
address, but instead request that OpenStack Networking allocates one from the pool. Allocate a
floating IP from the previously created pool:
# neutron floatingip-create public
+---------------------+--------------------------------------+
| Field
| Value
|
+---------------------+--------------------------------------+
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Red Hat OpenStack Platform 8 Networking Guide
| fixed_ip_address
|
|
| floating_ip_address | 192.168.100.20
|
| floating_network_id | 7a03e6bc-234d-402b-9fb2-0af06c85a8a3 |
| id
| 9d7e2603482d
|
| port_id
|
|
| router_id
|
|
| status
| ACTIVE
|
| tenant_id
| 9e67d44eab334f07bf82fa1b17d824b6
|
+---------------------+--------------------------------------+
With the IP address allocated, you can assign it to a particular instance. Locate the ID of the port
associated with your instance (this will match the fixed IP address allocated to the instance). This
port ID is used in the following step to associate the instance’s port ID with the floating IP address
ID. You can further distinguish the correct port ID by ensuring the MAC address in the third column
matches the one on the instance.
# neutron port-list
+--------+------+-------------+-------------------------------------------------------+
| id
| name | mac_address | fixed_ips
|
+--------+------+-------------+-------------------------------------------------------+
| ce8320 |
| 3e:37:09:4b | {"subnet_id": "361f27", "ip_address":
"192.168.100.2"} |
| d88926 |
| 3e:1d:ea:31 | {"subnet_id": "361f27", "ip_address":
"192.168.100.5"} |
| 8190ab |
| 3e:a3:3d:2f | {"subnet_id": "b74dbb", "ip_address":
"10.10.1.25"}|
+--------+------+-------------+-------------------------------------------------------+
Use the neutron command to associate the floating IP address with the desired port ID of an
instance:
# neutron floatingip-associate 9d7e2603482d 8190ab
3.12. Create multiple floating IP pools
OpenStack Networking supports one floating IP pool per L3 agent. Therefore, scaling out your L3
agents allows you to create additional floating IP pools.
Note
Ensure that handle_internal_only_routers in /etc/neutron/neutron.conf is configured to
True for only one L3 agent in your environment. This option configures the L3 agent to
manage only non-external routers.
3.13. Bridge the physical network
The procedure below enables you to bridge your virtual network to the physical network to enable
connectivity to and from virtual instances. In this procedure, the example physical eth0 interface is
mapped to the br-ex bridge; the virtual bridge acts as the intermediary between the physical network
30
CHAPTER 3. COMMON ADMINISTRATIVE TASKS
and any virtual networks. As a result, all traffic traversing eth0 uses the configured Open vSwitch to
reach instances. Map a physical NIC to the virtual Open vSwitch bridge:
Note
IPADDR, NETMASK GATEWAY, and DNS1 (name server) must be updated to match
your network.
# vi /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
TYPE=OVSPort
DEVICETYPE=ovs
OVS_BRIDGE=br-ex
ONBOOT=yes
Configure the virtual bridge with the IP address details that were
previously allocated to eth0:
# vi /etc/sysconfig/network-scripts/ifcfg-br-ex
DEVICE=br-ex
DEVICETYPE=ovs
TYPE=OVSBridge
BOOTPROTO=static
IPADDR=192.168.120.10
NETMASK=255.255.255.0
GATEWAY=192.168.120.1
DNS1=192.168.120.1
ONBOOT=yes
You can now assign floating IP addresses to instances and make them available to the physical
network.
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Red Hat OpenStack Platform 8 Networking Guide
CHAPTER 4. PLANNING IP ADDRESS USAGE
An OpenStack deployment can consume a larger number of IP addresses than might be expected.
This section aims to help with correctly anticipating the quantity of addresses required, and explains
where they will be used.
Note
VIPs (also known as Virtual IP Addresses) - VIP addresses host HA services, and are
basically an IP address shared between multiple controller nodes.
4.1. Using multiple VLANs
When planning your OpenStack deployment, you might begin with a number of these subnets, from
which you would be expected to allocate how the individual addresses will be used. Having multiple
subnets allows you to segregate traffic between systems into VLANs. For example, you would not
generally want management or API traffic to share the same network as systems serving web traffic.
Traffic between VLANs will also need to traverse through a router, which represents an opportunity
to have firewalls in place to further govern traffic flow.
4.2. Isolating VLAN traffic
You would typically allocate separate VLANs for the different types of network traffic you will host.
For example, you could have separate VLANs for each of these types of networks. Of these, only
the External network needs to be routable to the external physical network. In Red Hat OpenStack
Platform 8, DHCP services are provided by the director.
Note
Not all of the isolated VLANs in this section will be required for every OpenStack
deployment. For example, if your cloud users don’t need to create ad hoc virtual networks
on demand, then you may not require a tenant network; if you just need each VM to
connect directly to the same switch as any other physical system, then you probably just
need to connect your Compute nodes directly to a provider network and have your
instances use that provider network directly.
Provisioning network - This VLAN is dedicated to deploying new nodes using director over
PXE boot. OpenStack Orchestration (heat) installs OpenStack onto the overcloud baremetal
servers; these are attached to the physical network to receive the platform installation image
from the undercloud infrastructure.
Internal API network - The Internal API network is used for communication between the
OpenStack services, and covers API communication, RPC messages, and database
communication. In addition, this network is used for operational messages between controller
nodes. When planning your IP address allocation, note that each API service requires its own IP
address. Specifically, an IP address is required for each of these services:
vip-msg (ampq)
vip-keystone-int
vip-glance-int
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CHAPTER 4. PLANNING IP ADDRESS USAGE
vip-cinder-int
vip-nova-int
vip-neutron-int
vip-horizon-int
vip-heat-int
vip-ceilometer-int
vip-swift-int
vip-keystone-pub
vip-glance-pub
vip-cinder-pub
vip-nova-pub
vip-neutron-pub
vip-horizon-pub
vip-heat-pub
vip-ceilometer-pub
vip-swift-pub
Note
When using High Availability, Pacemaker expects to be able to move the VIP addresses
between the physical nodes.
Storage - Block Storage, NFS, iSCSI, among others. Ideally, this would be isolated to separate
physical Ethernet links for performance reasons.
Storage Management - OpenStack Object Storage (swift) uses this network to synchronise data
objects between participating replica nodes. The proxy service acts as the intermediary interface
between user requests and the underlying storage layer. The proxy receives incoming requests
and locates the necessary replica to retrieve the requested data. Services that use a Ceph back
end connect over the Storage Management network, since they do not interact with Ceph
directly but rather use the frontend service. Note that the RBD driver is an exception; this traffic
connects directly to Ceph.
Tenant networks - Neutron provides each tenant with their own networks using either VLAN
segregation (where each tenant network is a network VLAN), or tunneling via VXLAN or GRE.
Network traffic is isolated within each tenant network. Each tenant network has an IP subnet
associated with it, and multiple tenant networks may use the same addresses.
External - The External network hosts the public API endpoints and connections to the
Dashboard (horizon). You can also optionally use this same network for SNAT, but this is not a
requirement. In a production deployment, you will likely use a separate network for floating IP
addresses and NAT.
Provider networks - These networks allows instances to be attached to existing network
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Red Hat OpenStack Platform 8 Networking Guide
infrastructure. You can use provider networks to map directly to an existing physical network in
the data center, using flat networking or VLAN tags. This allows an instance to share the same
layer-2 network as a system external to the OpenStack Networking infrastructure.
4.3. IP address consumption
The following systems will consume IP addresses from your allocated range:
Physical nodes - Each physical NIC will require one IP address; it is common practice to
dedicate physical NICs to specific functions. For example, management and NFS traffic would
each be allocated their own physical NICs (sometimes with multiple NICs connecting across to
different switches for redundancy purposes).
Virtual IPs (VIPs) for High Availability - You can expect to allocate around 1 to 3 for each
network shared between controller nodes.
4.4. Virtual Networking
These virtual resources consume IP addresses in OpenStack Networking. These are considered
local to the cloud infrastructure, and do not need to be reachable by systems in the external physical
network:
Tenant networks - Each tenant network will require a subnet from which it will allocate IP
addresses to instances.
Virtual routers - Each router interface plugging into a subnet will require one IP address
Instances - Each instance will require an address from the tenant subnet they are hosted in. If
ingress traffic is needed, an additional floating IP address will need to be allocated from the
designated external network.
Management traffic - Includes OpenStack Services and API traffic. In Red Hat OpenStack
Platform 8, requirements for virtual IP addresses have been reduced; all services will instead
share a small number of VIPs. API, RPC and database services will communicate on the internal
API VIP.
4.5. Example network plan
This example allocates a number of networks to accommodate seven subnets, with a quantity of
addresses for each:
Table 4.1. Example subnet plan
Subnet name
34
Address range
Number of addresses
Subnet Mask
Provisioning network
192.168.100.1 192.168.100.250
250
255.255.255.0
Internal API network
172.16.1.10 172.16.1.250
241
255.255.255.0
CHAPTER 4. PLANNING IP ADDRESS USAGE
Subnet name
Address range
Number of addresses
Subnet Mask
Storage
172.16.2.10 172.16.2.250
241
255.255.255.0
Storage Management
172.16.3.10 172.16.3.250
241
255.255.255.0
Tenant network
(GRE/VXLAN)
172.19.4.10 172.16.4.250
241
255.255.255.0
10.1.2.10 - 10.1.3.222
469
255.255.254.0
10.10.3.10 10.10.3.250
241
255.255.252.0
External network (incl.
floating IPs)
Provider network
(infrastructure)
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Red Hat OpenStack Platform 8 Networking Guide
CHAPTER 5. REVIEW OPENSTACK NETWORKING ROUTER
PORTS
Virtual routers in OpenStack Networking use ports to interconnect with subnets. You can review the
state of these ports to determine whether they’re connecting as expected.
5.1. View current port status
This procedure lists all the ports attached to a particular router, then demonstrates how to retrieve a
port’s state (DOWN or ACTIVE).
1. View all the ports attached to the router named r1:
#
neutron router-port-list r1
Example result:
+--------------------------------------+------+------------------+-------------------------------------------------------------------------------------+
| id
| name | mac_address
|
fixed_ips
|
+--------------------------------------+------+------------------+-------------------------------------------------------------------------------------+
| b58d26f0-cc03-43c1-ab23-ccdb1018252a |
| fa:16:3e:94:a7:df |
{"subnet_id": "a592fdba-babd-48e0-96e8-2dd9117614d3", "ip_address":
"192.168.200.1"} |
| c45e998d-98a1-4b23-bb41-5d24797a12a4 |
| fa:16:3e:ee:6a:f7 |
{"subnet_id": "43f8f625-c773-4f18-a691-fd4ebfb3be54", "ip_address":
"172.24.4.225"} |
+--------------------------------------+------+------------------+-------------------------------------------------------------------------------------+
2. View the details of each port by running this command against its ID (the value in the left column).
The result includes the port’s status, indicated in the following example as having an ACTIVE state:
# neutron port-show b58d26f0-cc03-43c1-ab23-ccdb1018252a
Example result:
+-----------------------+-------------------------------------------------------------------------------------+
| Field
| Value
|
+-----------------------+-------------------------------------------------------------------------------------+
| admin_state_up
| True
|
| allowed_address_pairs |
|
| binding:host_id
| node.example.com
36
CHAPTER 5. REVIEW OPENSTACK NETWORKING ROUTER PORTS
|
| binding:profile
| {}
|
| binding:vif_details
| {"port_filter": true, "ovs_hybrid_plug":
true}
|
| binding:vif_type
| ovs
|
| binding:vnic_type
| normal
|
| device_id
| 49c6ebdc-0e62-49ad-a9ca-58cea464472f
|
| device_owner
| network:router_interface
|
| extra_dhcp_opts
|
|
| fixed_ips
| {"subnet_id": "a592fdba-babd-48e0-96e82dd9117614d3", "ip_address": "192.168.200.1"} |
| id
| b58d26f0-cc03-43c1-ab23-ccdb1018252a
|
| mac_address
| fa:16:3e:94:a7:df
|
| name
|
|
| network_id
| 63c24160-47ac-4140-903d-8f9a670b0ca4
|
| security_groups
|
|
| status
| ACTIVE
|
| tenant_id
| d588d1112e0f496fb6cac22f9be45d49
|
+-----------------------+-------------------------------------------------------------------------------------+
Perform this step for each port to retrieve its status.
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Red Hat OpenStack Platform 8 Networking Guide
CHAPTER 6. TROUBLESHOOT PROVIDER NETWORKS
A deployment of virtual routers and switches, also known as software-defined networking (SDN),
may seem to introduce complexity at first glance. However, the diagnostic process of
troubleshooting network connectivity in OpenStack Networking is similar to that of physical
networks. The virtual infrastructure can be considered a trunked extension of the physical network,
rather than a wholly separate environment.
6.1. Topics covered
Basic ping testing
Troubleshooting VLAN networks
Troubleshooting from within tenant networks
6.2. Basic ping testing
The ping command is a useful tool for analyzing network connectivity problems. The results serve as
a basic indicator of network connectivity, but might not entirely exclude all connectivity issues, such
as a firewall blocking the actual application traffic. The ping command works by sending traffic to
specified destinations, and then reports back whether the attempts were successful.
Note
The ping command expects that ICMP traffic is allowed to traverse any intermediary
firewalls.
Ping tests are most useful when run from the machine experiencing network issues, so it may be
necessary to connect to the command line via the VNC management console if the machine seems
to be completely offline.
For example, the ping test command below needs to validate multiple layers of network
infrastructure in order to succeed; name resolution, IP routing, and network switching will all need to
be functioning correctly:
$ ping www.redhat.com
PING e1890.b.akamaiedge.net (125.56.247.214) 56(84) bytes of data.
64 bytes from a125-56.247-214.deploy.akamaitechnologies.com
(125.56.247.214): icmp_seq=1 ttl=54 time=13.4 ms
64 bytes from a125-56.247-214.deploy.akamaitechnologies.com
(125.56.247.214): icmp_seq=2 ttl=54 time=13.5 ms
64 bytes from a125-56.247-214.deploy.akamaitechnologies.com
(125.56.247.214): icmp_seq=3 ttl=54 time=13.4 ms
^C
You can terminate the ping command with Ctrl-c, after which a summary of the results is presented.
Zero packet loss indicates that the connection was timeous and stable:
--- e1890.b.akamaiedge.net ping statistics --3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 13.461/13.498/13.541/0.100 ms
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CHAPTER 6. TROUBLESHOOT PROVIDER NETWORKS
In addition, the results of a ping test can be very revealing, depending on which destination gets
tested. For example, in the following diagram VM1 is experiencing some form of connectivity issue.
The possible destinations are numbered in red, and the conclusions drawn from a successful or
failed result are presented:
1. The internet - a common first step is to send a ping test to an internet location, such as
www.redhat.com.
Success: This test indicates that all the various network points in between are working as
expected. This includes the virtual and physical network infrastructure.
Failure: There are various ways in which a ping test to a distant internet location can fail. If other
machines on your network are able to successfully ping the internet, that proves the internet
connection is working, and it’s time to bring the troubleshooting closer to home.
2. Physical router - This is the router interface designated by the network administrator to direct
traffic onward to external destinations.
Success: Ping tests to the default gateway examine whether the local network and underlying
switches are functioning. These packets don’t traverse the router, so they do not prove if there’s
a routing issue present on the default gateway.
Failure: This indicates that the problem lies between VM1 and the default gateway. The
router/switches might be down, or you may be using an incorrect default gateway. Compare the
configuration with that on another server that is known to be working. Try pinging another server
on the local network.
3. Neutron router - This is the virtual SDN (Software-defined Networking) router used by RHEL
OpenStack to direct the traffic of virtual machines.
Success: Firewall is allowing ICMP traffic, the Networking node is online.
Failure: Confirm whether ICMP traffic is permitted in the instance’s security group. Check that
the Networking node is online, and all the required services are running.
4. Physical switch - The physical switch’s role is to manage traffic between nodes on the same
physical network.
Success: Traffic sent by a VM to the physical switch will need to pass through the virtual network
infrastructure, indicating that this segment is functioning as expected.
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Red Hat OpenStack Platform 8 Networking Guide
Failure: Is the physical switch port configured to trunk the required VLANs?
5. VM2 - Attempt to ping a VM on the same subnet, on the same Compute node.
Success: The NIC driver and basic IP configuration on VM1 are functional.
Failure: Validate the network configuration on VM1. Or, VM2’s firewall might simply be blocking
ping traffic.
6.3. Troubleshooting VLAN networks
OpenStack Networking is able to trunk VLAN networks through to the SDN switches. Support for
VLAN-tagged provider networks means that virtual instances are able to integrate with server
subnets in the physical network.
To troubleshoot connectivity to a VLAN Provider network, attempt to ping the gateway IP designated
when the network was created. For example, if you created the network with these commands:
# neutron net-create provider --provider:network_type=vlan -provider:physical_network=phy-eno1 --provider:segmentation_id=120 -router:external=True
# neutron subnet-create "provider" --allocation-pool
start=192.168.120.1,end=192.168.120.253 --disable-dhcp --gateway
192.168.120.254 192.168.120.0/24
Then you’ll want to attempt to ping the defined gateway IP of 192.168.120.254
If that fails, confirm that you have network flow for the associated VLAN (as defined during network
creation). In the example above, OpenStack Networking is configured to trunk VLAN 120 to the
provider network. This option is set using the parameter --provider:segmentation_id=120.
Confirm the VLAN flow on the bridge interface, in this case it’s named br-ex:
# ovs-ofctl dump-flows br-ex
NXST_FLOW reply (xid=0x4):
cookie=0x0, duration=987.521s, table=0, n_packets=67897,
n_bytes=14065247, idle_age=0, priority=1 actions=NORMAL
cookie=0x0, duration=986.979s, table=0, n_packets=8, n_bytes=648,
idle_age=977, priority=2,in_port=12 actions=drop
6.3.1. Review the VLAN configuration and log files
OpenStack Networking (neutron) agents - Use the neutron command to verify that all agents
are up and registered with the correct names:
# neutron agent-list
+--------------------------------------+--------------------+----------------------+-------+----------------+
| id
| agent_type
| host
| alive | admin_state_up |
+--------------------------------------+--------------------+----------------------+-------+----------------+
| a08397a8-6600-437d-9013-b2c5b3730c0c | Metadata agent
|
rhelosp.example.com
| :-)
| True
|
| a5153cd2-5881-4fc8-b0ad-be0c97734e6a | L3 agent
|
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CHAPTER 6. TROUBLESHOOT PROVIDER NETWORKS
rhelosp.example.com
| :-)
| True
|
| b54f0be7-c555-43da-ad19-5593a075ddf0 | DHCP agent
|
rhelosp.example.com
| :-)
| True
|
| d2be3cb0-4010-4458-b459-c5eb0d4d354b | Open vSwitch agent |
rhelosp.example.com
| :-)
| True
|
+--------------------------------------+--------------------+----------------------+-------+----------------+
Review /var/log/neutron/openvswitch-agent.log - this log should provide confirmation that the
creation process used the ovs-ofctl command to configure VLAN trunking.
Validate external_network_bridge in the /etc/neutron/l3_agent.ini file. A hardcoded value
here won’t allow you to use a provider network via the L3-agent, and won’t create the necessary
flows.
Check network_vlan_ranges in the /etc/neutron/plugin.ini file. You don’t need to specify the
numeric VLAN ID if it’s a provider network. The only time you need to specify the ID(s) here is if
you’re using VLAN isolated tenant networks.
6.4. Troubleshooting from within tenant networks
In OpenStack Networking, all tenant traffic is contained within network namespaces. This allows
tenants to configure networks without interfering with each other. For example, network
namespaces allow different tenants to have the same subnet range of 192.168.1.1/24 without
resulting in any interference between them.
To begin troubleshooting a tenant network, first determine which network namespace contains the
network:
1. List all the tenant networks using the neutron command:
# neutron net-list
+--------------------------------------+-------------+------------------------------------------------------+
| id
| name
| subnets
|
+--------------------------------------+-------------+------------------------------------------------------+
| 9cb32fe0-d7fb-432c-b116-f483c6497b08 | web-servers | 453d6769-fcde4796-a205-66ee01680bba 192.168.212.0/24 |
| a0cc8cdd-575f-4788-a3e3-5df8c6d0dd81 | private
| c1e58160-707f44a7-bf94-8694f29e74d3 10.0.0.0/24
|
| baadd774-87e9-4e97-a055-326bb422b29b | private
| 340c58e1-7fe74cf2-96a7-96a0a4ff3231 192.168.200.0/24 |
| 24ba3a36-5645-4f46-be47-f6af2a7d8af2 | public
| 35f3d2cb-6e4b4527-a932-952a395c4bb3 172.24.4.224/28 |
+--------------------------------------+-------------+------------------------------------------------------+
In this example, we’ll be examining the web-servers network. Make a note of the id value in the
web-server row (in this case, its 9cb32fe0-d7fb-432c-b116-f483c6497b08). This value is appended
to the network namespace, which will help you identify in the next step.
2. List all the network namespaces using the ip command:
# ip netns list
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qdhcp-9cb32fe0-d7fb-432c-b116-f483c6497b08
qrouter-31680a1c-9b3e-4906-bd69-cb39ed5faa01
qrouter-62ed467e-abae-4ab4-87f4-13a9937fbd6b
qdhcp-a0cc8cdd-575f-4788-a3e3-5df8c6d0dd81
qrouter-e9281608-52a6-4576-86a6-92955df46f56
In the result there is a namespace that matches the web-server network id. In this example it’s
presented as qdhcp-9cb32fe0-d7fb-432c-b116-f483c6497b08.
3. Examine the configuration of the web-servers network by running commands within the
namespace. This is done by prefixing the troubleshooting commands with ip netns exec
(namespace). For example:
a) View the routing table of the web-servers network:
# ip netns exec qrouter-62ed467e-abae-4ab4-87f4-13a9937fbd6b route -n
Kernel IP routing table
Destination
Gateway
Use Iface
0.0.0.0
172.24.4.225
0 qg-8d128f89-87
172.24.4.224
0.0.0.0
0 qg-8d128f89-87
192.168.200.0
0.0.0.0
0 qr-8efd6357-96
Genmask
Flags Metric Ref
0.0.0.0
UG
0
0
255.255.255.240 U
0
0
255.255.255.0
0
0
U
b) View the routing table of the web-servers network:
# ip netns exec qrouter-62ed467e-abae-4ab4-87f4-13a9937fbd6b route -n
Kernel IP routing table
Destination
Gateway
Use Iface
0.0.0.0
172.24.4.225
0 qg-8d128f89-87
172.24.4.224
0.0.0.0
0 qg-8d128f89-87
192.168.200.0
0.0.0.0
0 qr-8efd6357-96
Genmask
Flags Metric Ref
0.0.0.0
UG
0
0
255.255.255.240 U
0
0
255.255.255.0
0
0
U
6.4.1. Perform advanced ICMP testing within the namespace
1. Capture ICMP traffic using the tcpdump command.
# ip netns exec qrouter-62ed467e-abae-4ab4-87f4-13a9937fbd6b tcpdump qnntpi any icmp
There may not be any output until you perform the next step:
2. In a separate command line window, perform a ping test to an external network:
# ip netns exec qrouter-62ed467e-abae-4ab4-87f4-13a9937fbd6b
www.redhat.com
42
ping
CHAPTER 6. TROUBLESHOOT PROVIDER NETWORKS
3. In the terminal running the tcpdump session, you will observe detailed results of the ping test.
tcpdump: listening on any, link-type LINUX_SLL (Linux cooked), capture
size 65535 bytes
IP (tos 0xc0, ttl 64, id 55447, offset 0, flags [none], proto ICMP (1),
length 88)
172.24.4.228 > 172.24.4.228: ICMP host 192.168.200.20 unreachable,
length 68
IP (tos 0x0, ttl 64, id 22976, offset 0, flags [DF], proto UDP (17),
length 60)
172.24.4.228.40278 > 192.168.200.21: [bad udp cksum 0xfa7b ->
0xe235!] UDP, length 32
Note
When performing a tcpdump analysis of traffic, you might observe the responding
packets heading to the router interface rather than the instance. This is expected
behaviour, as the qrouter performs DNAT on the return packets.
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CHAPTER 7. CONNECT AN INSTANCE TO THE PHYSICAL
NETWORK
This chapter explains how to use provider networks to connect instances directly to an external
network.
Overview of the OpenStack Networking topology:
OpenStack Networking (neutron) has two categories of services distributed across a number of node
types.
Neutron API server - This service runs the OpenStack Networking API server, which provides
the API for end-users and services to interact with OpenStack Networking. This server also
integrates with the underlying database to store and retrieve tenant network, router, and
loadbalancer details, among others.
Neutron agents - These are the services that perform the network functions for OpenStack
Networking:
neutron-dhcp-agent - manages DHCP IP addressing for tenant private networks.
neutron-l3-agent - performs layer 3 routing between tenant private networks, the
external network, and others.
neutron-lbaas-agent - provisions the LBaaS routers created by tenants.
Compute node - This node hosts the hypervisor that runs the virtual machines, also known as
instances. A Compute node must to be wired directly to the network in order to provide external
connectivity for instances.
Service placement:
The OpenStack Networking services can either run together on the same physical server, or on
separate dedicated servers, which are named according to their roles:
Controller node - The server that runs API service.
Network node - The server that runs the OpenStack Networking agents.
Compute node - The hypervisor server that hosts the instances.
The steps in this chapter assume that your environment has deployed these three node types. If
your deployment has both the Controller and Network node roles on the same physical node, then
the steps from both sections must be performed on that server. This also applies for a High
Availability (HA) environment, where all three nodes might be running the Controller node and
Network node services with HA. As a result, sections applicable to Controller and Network nodes will
need to be performed on all three nodes.
7.1. Using Flat Provider Networks
This procedure creates flat provider networks that can connect instances directly to external
networks. You would do this if you have multiple physical networks (for example, physnet1,
physnet2) and separate physical interfaces (eth0 -> physnet1, and eth1 -> physnet2),
and you need to connect each Compute node and Network node to those external networks.
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CHAPTER 7. CONNECT AN INSTANCE TO THE PHYSICAL NETWORK
Note
If you want to connect multiple VLAN-tagged interfaces (on a single NIC) to multiple
provider networks, please refer to: VLAN provider networks.
Configure the Controller nodes:
1. Edit /etc/neutron/plugin.ini (which is symlinked to
/etc/neutron/plugins/ml2/ml2_conf.ini) and add flat to the existing list of values, and
set flat_networks to *:
type_drivers = vxlan,flat
flat_networks =*
2. Create a flat external network and associate it with the configured physical_network. Creating
it as a shared network will allow other users to connect their instances directly to it:
neutron net-create public01 --provider:network_type flat -provider:physical_network physnet1 --router:external=True --shared
3. Create a subnet within this external network using neutron subnet-create or the OpenStack
Dashboard.
4. Restart the neutron-server service to apply this change:
# systemctl restart neutron-server.service
Configure the Network node and Compute nodes:
These steps must be completed on the Network node and the Compute nodes. As a result, the
nodes will connect to the external network, and will allow instances to communicate directly with the
external network.
1. Create the Open vSwitch bridge and port. This step creates the external network bridge (br-ex)
and adds a corresponding port (eth1):
i. Edit /etc/sysconfig/network-scripts/ifcfg-eth1:
DEVICE=eth1
TYPE=OVSPort
DEVICETYPE=ovs
OVS_BRIDGE=br-ex
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=none
ii. Edit /etc/sysconfig/network-scripts/ifcfg-br-ex:
DEVICE=br-ex
TYPE=OVSBridge
DEVICETYPE=ovs
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Red Hat OpenStack Platform 8 Networking Guide
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=none
2. Restart the network service for the changes to take effect:
# systemctl restart network.service
3. Configure the physical networks in
/etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini and map the bridge to
the physical network:
Note
For more information on configuring bridge_mappings, see the Configure Bridge
Mappings chapter in this guide.
bridge_mappings = physnet1:br-ex
4. Restart the neutron-openvswitch-agent service on the Network and Compute nodes for the
changes to take effect:
systemctl restart neutron-openvswitch-agent
Configure the Network node:
1. Set external_network_bridge = to an empty value in /etc/neutron/l3-agent.ini.
This enables the use of external provider networks.
# Name of bridge used for external network traffic. This should be set
to
# empty value for the linux bridge
external_network_bridge =
2. Restart neutron-l3-agent for the changes to take effect:
systemctl restart neutron-l3-agent.service
Note
If there are multiple flat provider networks, each of them should have separate physical
interface and bridge to connect them to external network. Please configure the ifcfg-*
scripts appropriately and use comma-separated list for each network when specifying
them in bridge_mappings. For more information on configuring bridge_mappings,
see the Configure Bridge Mappings chapter in this guide.
Connect an instance to the external network:
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CHAPTER 7. CONNECT AN INSTANCE TO THE PHYSICAL NETWORK
With the network created, you can now connect an instance to it and test connectivity:
1. Create a new instance.
2. Use the Networking tab in the dashboard to add the new instance directly to the newly-created
external network.
How does the packet flow work?
With flat provider networking configured, this section describes in detail how traffic flows to and from
an instance.
7.1.1. The flow of outgoing traffic
The packet flow for traffic leaving an instance and arriving directly at an external network: Once you
configure br-ex, add the physical interface, and spawn an instance to a Compute node, your
resulting interfaces and bridges will be similiar to those in the diagram below:
1. Packets leaving the eth0 interface of the instance will first arrive at the linux bridge qbr-xx.
2. Bridge qbr-xx is connected to br-int using veth pair qvb-xx <-> qvo-xxx.
3. Interface qvb-xx is connected to the qbr-xx linux bridge, and qvo-xx is connected to the brint Open vSwitch (OVS) bridge.
The configuration of qbr-xx on the Linux bridge:
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qbr269d4d73-e7 8000.061943266ebb no
tap269d4d73-e7
qvb269d4d73-e7
The configuration of qvo-xx on br-int:
Bridge br-int
fail_mode: secure
Interface "qvof63599ba-8f"
Port "qvo269d4d73-e7"
tag: 5
Interface "qvo269d4d73-e7"
Note
Port qvo-xx is tagged with the internal VLAN tag associated with the flat provider
network. In this example, the VLAN tag is 5. Once the packet reaches qvo-xx, the VLAN
tag is appended to the packet header.
The packet is then moved to the br-ex OVS bridge using the patch-peer int-br-ex <-> phybr-ex.
Example configuration of the patch-peer on br-int:
Bridge br-int
fail_mode: secure
Port int-br-ex
Interface int-br-ex
type: patch
options: {peer=phy-br-ex}
Example configuration of the patch-peer on br-ex:
Bridge br-ex
Port phy-br-ex
Interface phy-br-ex
type: patch
options: {peer=int-br-ex}
Port br-ex
Interface br-ex
type: internal
When this packet reaches phy-br-ex on br-ex, an OVS flow inside br-ex strips the VLAN tag (5)
and forwards it to the physical interface.
In the example below, the output shows the port number of phy-br-ex as 2.
# ovs-ofctl show br-ex
OFPT_FEATURES_REPLY (xid=0x2): dpid:00003440b5c90dc6
n_tables:254, n_buffers:256
capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS
ARP_MATCH_IP
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CHAPTER 7. CONNECT AN INSTANCE TO THE PHYSICAL NETWORK
actions: OUTPUT SET_VLAN_VID SET_VLAN_PCP STRIP_VLAN SET_DL_SRC
SET_DL_DST SET_NW_SRC SET_NW_DST SET_NW_TOS SET_TP_SRC SET_TP_DST
ENQUEUE
2(phy-br-ex): addr:ba:b5:7b:ae:5c:a2
config:
0
state:
0
speed: 0 Mbps now, 0 Mbps max
The output below shows any packet that arrives on phy-br-ex (in_port=2) with a VLAN tag of 5
(dl_vlan=5). In addition, the VLAN tag is stripped away and the packet is forwarded
(actions=strip_vlan,NORMAL).
# ovs-ofctl dump-flows br-ex
NXST_FLOW reply (xid=0x4):
cookie=0x0, duration=4703.491s, table=0, n_packets=3620,
n_bytes=333744, idle_age=0, priority=1 actions=NORMAL
cookie=0x0, duration=3890.038s, table=0, n_packets=13, n_bytes=1714,
idle_age=3764, priority=4,in_port=2,dl_vlan=5 actions=strip_vlan,NORMAL
cookie=0x0, duration=4702.644s, table=0, n_packets=10650,
n_bytes=447632, idle_age=0, priority=2,in_port=2 actions=drop
This packet is then forwarded to the physical interface. If the physical interface is another VLANtagged interface, then the interface will add the tag to the packet.
7.1.2. The flow of incoming traffic
This section describes the flow of incoming traffic from the external network until it arrives at the
instance’s interface.
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1. Incoming traffic first arrives at eth1 on the physical node.
2. The packet is then passed to the br-ex bridge.
3. The packet then moves to br-int using the patch-peer phy-br-ex <--> int-br-ex.
In the example below, int-br-ex uses port number 15. See the entry containing 15(int-brex):
ovs-ofctl show br-int
OFPT_FEATURES_REPLY (xid=0x2): dpid:00004e67212f644d
n_tables:254, n_buffers:256
capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS
ARP_MATCH_IP
actions: OUTPUT SET_VLAN_VID SET_VLAN_PCP STRIP_VLAN SET_DL_SRC
SET_DL_DST SET_NW_SRC SET_NW_DST SET_NW_TOS SET_TP_SRC SET_TP_DST
ENQUEUE
15(int-br-ex): addr:12:4e:44:a9:50:f4
config:
0
state:
0
speed: 0 Mbps now, 0 Mbps max
Observing the traffic flow on br-int
1. When the packet arrives at int-br-ex, an OVS flow rule within the br-int bridge amends the
packet to add the internal VLAN tag 5. See the entry for actions=mod_vlan_vid:5:
# ovs-ofctl dump-flows br-int
NXST_FLOW reply (xid=0x4):
cookie=0x0, duration=5351.536s, table=0, n_packets=12118,
n_bytes=510456, idle_age=0, priority=1 actions=NORMAL
cookie=0x0, duration=4537.553s, table=0, n_packets=3489,
n_bytes=321696, idle_age=0, priority=3,in_port=15,vlan_tci=0x0000
actions=mod_vlan_vid:5,NORMAL
cookie=0x0, duration=5350.365s, table=0, n_packets=628, n_bytes=57892,
idle_age=4538, priority=2,in_port=15 actions=drop
cookie=0x0, duration=5351.432s, table=23, n_packets=0, n_bytes=0,
idle_age=5351, priority=0 actions=drop
2. The second rule manages packets that arrive on int-br-ex (in_port=15) with no VLAN tag
(vlan_tci=0x0000): It adds VLAN tag 5 to the packet (actions=mod_vlan_vid:5,NORMAL) and
forwards it on to qvo-xxx.
3. qvo-xxx accepts the packet and forwards to qvb-xx, after stripping the away the VLAN tag.
4. The packet then reaches the instance.
Note
VLAN tag 5 is an example VLAN that was used on a test Compute node with a flat
provider network; this value was assigned automatically by neutron-openvswitchagent. This value may be different for your own flat provider network, and it can differ for
the same network on two separate Compute nodes.
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CHAPTER 7. CONNECT AN INSTANCE TO THE PHYSICAL NETWORK
7.1.3. Troubleshooting
The output provided in the section above - How does the packet flow work? - provides sufficient
debugging information for troubleshooting a flat provider network, should anything go wrong. The
steps below would further assist with the troubleshooting process.
1. Review bridge_mappings:
Verify that physical network name used (for example, physnet1) is consistent with the contents of
the bridge_mapping configuration. For example:
# grep bridge_mapping
/etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini
bridge_mappings = physnet1:br-ex
# neutron net-show provider-flat
...
| provider:physical_network | physnet1
...
2. Review the network configuration:
Confirm that the network is created as external, and uses the flat type:
# neutron net-show provider-flat
...
| provider:network_type
| flat
| router:external
| True
...
|
|
3. Review the patch-peer:
Run ovs-vsctl show, and verify that br-int and br-ex is connected using a patch-peer intbr-ex <--> phy-br-ex.
This connection is created when the neutron-openvswitch-agent service is restarted. But only
if bridge_mapping is correctly configured in
/etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini. Re-check the
bridge_mapping setting if this is not created, even after restarting the service.
Note
For more information on configuring bridge_mappings, see the Configure Bridge
Mappings chapter in this guide.
4. Review the network flows:
Run ovs-ofctl dump-flows br-ex and ovs-ofctl dump-flows br-int and review
whether the flows strip the internal VLAN IDs for outgoing packets, and add VLAN IDs for incoming
packets. This flow is first added when you spawn an instance to this network on a specific Compute
node.
If this flow is not created after spawning the instance, verify that the network is created as flat,
is external, and that the physical_network name is correct. In addition, review the
bridge_mapping settings.
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Red Hat OpenStack Platform 8 Networking Guide
Finally, review the ifcfg-br-ex and ifcfg-ethx configuration. Make sure that ethX is
definitely added as a port within br-ex, and that both of them have UP flag in the output of ip a.
For example, the output below shows eth1 is a port in br-ex:
Bridge br-ex
Port phy-br-ex
Interface phy-br-ex
type: patch
options: {peer=int-br-ex}
Port "eth1"
Interface "eth1"
The example below demonstrates that eth1 is configured as an OVS port, and that the kernel
knows to transfer all packets from the interface, and send them to the OVS bridge br-ex. This can
be observed in the entry: master ovs-system.
# ip a
5: eth1: mtu 1500 qdisc mq master
ovs-system state UP qlen 1000
7.2. Using VLAN provider networks
This procedure creates VLAN provider networks that can connect instances directly to external
networks. You would do this if you want to connect multiple VLAN-tagged interfaces (on a single
NIC) to multiple provider networks. This example uses a physical network called physnet1, with a
range of VLANs (171-172). The network nodes and compute nodes are connected to the physical
network using a physical interface on them called eth1. The switch ports to which these interfaces
are connected must be configured to trunk the required VLAN ranges.
The following procedures configure the VLAN provider networks using the example VLAN IDs and
names given above.
Configure the Controller nodes:
1. Enable the vlan mechanism driver by editing /etc/neutron/plugin.ini (symlinked to
/etc/neutron/plugins/ml2/ml2_conf.ini), and add vlan to the existing list of values. For
example:
[ml2]
type_drivers = vxlan,flat,vlan
2. Configure the network_vlan_ranges setting to reflect the physical network and VLAN ranges
in use. For example:
[ml2_type_vlan]
network_vlan_ranges=physnet1:171:172
3. Restart the neutron-server service to apply the changes:
systemctl restart neutron-server
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CHAPTER 7. CONNECT AN INSTANCE TO THE PHYSICAL NETWORK
4. Create the external networks as a vlan-type, and associate them to the configured
physical_network. Create it as a --shared network to let other users directly connect instances.
This example creates two networks: one for VLAN 171, and another for VLAN 172:
neutron net-create provider-vlan171 \
--provider:network_type vlan \
--router:external true \
--provider:physical_network physnet1 \
--provider:segmentation_id 171 --shared
neutron net-create provider-vlan172 \
--provider:network_type vlan \
--router:external true \
--provider:physical_network physnet1 \
--provider:segmentation_id 172 --shared
5. Create a number of subnets and configure them to use the external network. This is done using
either neutron subnet-create or the dashboard. You will want to make certain that the external
subnet details you have received from your network administrator are correctly associated with
each VLAN. In this example, VLAN 171 uses subnet 10.65.217.0/24 and VLAN 172 uses
10.65.218.0/24:
neutron subnet-create \
--name subnet-provider-171 provider-171 10.65.217.0/24 \
--enable-dhcp \
--gateway 10.65.217.254 \
neutron subnet-create \
--name subnet-provider-172 provider-172 10.65.218.0/24 \
--enable-dhcp \
--gateway 10.65.218.254 \
Configure the Network nodes and Compute nodes:
These steps must be performed on the Network node and Compute nodes. As a result, this will
connect the nodes to the external network, and permit instances to communicate directly with the
external network.
1. Create an external network bridge (br-ex), and associate a port (eth1) with it:
This example configures eth1 to use bre-ex:
/etc/sysconfig/network-scripts/ifcfg-eth1
DEVICE=eth1
TYPE=OVSPort
DEVICETYPE=ovs
OVS_BRIDGE=br-ex
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=none
This example configures the br-ex bridge:
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Red Hat OpenStack Platform 8 Networking Guide
/etc/sysconfig/network-scripts/ifcfg-br-ex:
DEVICE=br-ex
TYPE=OVSBridge
DEVICETYPE=ovs
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=none
2. Reboot the node, or restart the network service for the networking changes to take effect. For
example:
# systemctl restart network
3. Configure physical networks in
/etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini and map bridges
according to the physical network:
bridge_mappings = physnet1:br-ex
Note
For more information on configuring bridge_mappings, see the Configure Bridge
Mappings chapter in this guide.
4. Restart the neutron-openvswitch-agent service on the network nodes and compute nodes
for the changes to take effect:
systemctl restart neutron-openvswitch-agent
Configure the Network node:
1. Set external_network_bridge = to an empty value in /etc/neutron/l3-agent.ini.
This is required to use provider external networks, not bridge based external network where we will
add external_network_bridge = br-ex:
# Name of bridge used for external network traffic. This should be set
to
# empty value for the linux bridge
external_network_bridge =
2. Restart neutron-l3-agent for the changes to take effect.
systemctl restart neutron-l3-agent
3. Create a new instance and use the Networking tab in the dashboard to add the new instance
directly to the newly-created external network.
How does the packet flow work?
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CHAPTER 7. CONNECT AN INSTANCE TO THE PHYSICAL NETWORK
With VLAN provider networking configured, this section describes in detail how traffic flows to and
from an instance:
7.2.1. The flow of outgoing traffic
This section describes the packet flow for traffic leaving an instance and arriving directly to a VLAN
provider external network. This example uses two instances attached to the two VLAN networks
(171 and 172). Once you configure br-ex, add a physical interface to it, and spawn an instance to a
Compute node, your resulting interfaces and bridges will be similiar to those in the diagram below:
1. As illustrated above, packets leaving the instance’s eth0 first arrive at the linux bridge qbr-xx
connected to the instance.
2. qbr-xx is connected to br-int using veth pair qvb-xx <→ qvo-xxx.
3. qvb-xx is connected to the linux bridge qbr-xx and qvo-xx is connected to the Open vSwitch
bridge br-int.
Below is the configuration of qbr-xx on the Linux bridge.
Since there are two instances, there would two linux bridges:
# brctl show
bridge name bridge id STP enabled interfaces
qbr84878b78-63 8000.e6b3df9451e0 no qvb84878b78-63
tap84878b78-63
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qbr86257b61-5d 8000.3a3c888eeae6 no
tap86257b61-5d
qvb86257b61-5d
The configuration of qvo-xx on br-int:
options: {peer=phy-br-ex}
Port "qvo86257b61-5d"
tag: 3
Interface "qvo86257b61-5d"
Port "qvo84878b78-63"
tag: 2
Interface "qvo84878b78-63"
qvo-xx is tagged with the internal VLAN tag associated with the VLAN provider network. In this
example, the internal VLAN tag 2 is associated with the VLAN provider network provider-171
and VLAN tag 3 is associated with VLAN provider network provider-172. Once the packet
reaches qvo-xx, the packet header will get this VLAN tag added to it.
The packet is then moved to the br-ex OVS bridge using patch-peer int-br-ex <→ phy-brex. Example patch-peer on br-int:
Bridge br-int
fail_mode: secure
Port int-br-ex
Interface int-br-ex
type: patch
options: {peer=phy-br-ex}
Example configuration of the patch peer on br-ex:
Bridge br-ex
Port phy-br-ex
Interface phy-br-ex
type: patch
options: {peer=int-br-ex}
Port br-ex
Interface br-ex
type: internal
When this packet reaches phy-br-ex on br-ex, an OVS flow inside br-ex replaces the internal
VLAN tag with the actual VLAN tag associated with the VLAN provider network.
The output of the following command shows that the port number of phy-br-ex is 4:
# ovs-ofctl show br-ex
4(phy-br-ex): addr:32:e7:a1:6b:90:3e
config:
0
state:
0
speed: 0 Mbps now, 0 Mbps max
The below command displays any packet that arrives on phy-br-ex (in_port=4) which has VLAN
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CHAPTER 7. CONNECT AN INSTANCE TO THE PHYSICAL NETWORK
tag 2 (dl_vlan=2). Open vSwitch replaces the VLAN tag with 171
(actions=mod_vlan_vid:171,NORMAL) and forwards the packet on. It also shows any packet
that arrives on phy-br-ex (in_port=4) which has VLAN tag 3 (dl_vlan=3). Open vSwitch
replaces the VLAN tag with 172 (actions=mod_vlan_vid:172,NORMAL) and forwards the
packet on. These rules are automatically added by neutron-openvswitch-agent.
# ovs-ofctl dump-flows br-ex
NXST_FLOW reply (xid=0x4):
NXST_FLOW reply (xid=0x4):
cookie=0x0, duration=6527.527s, table=0, n_packets=29211,
n_bytes=2725576, idle_age=0, priority=1 actions=NORMAL
cookie=0x0, duration=2939.172s, table=0, n_packets=117, n_bytes=8296,
idle_age=58, priority=4,in_port=4,dl_vlan=3
actions=mod_vlan_vid:172,NORMAL
cookie=0x0, duration=6111.389s, table=0, n_packets=145, n_bytes=9368,
idle_age=98, priority=4,in_port=4,dl_vlan=2
actions=mod_vlan_vid:171,NORMAL
cookie=0x0, duration=6526.675s, table=0, n_packets=82, n_bytes=6700,
idle_age=2462, priority=2,in_port=4 actions=drop
This packet is then forwarded to physical interface eth1.
7.2.2. The flow of incoming traffic
An incoming packet for the instance from external network first reaches eth1, then arrives at brex.
From br-ex, the packet is moved to br-int via patch-peer phy-br-ex <-> int-br-ex.
The below command shows int-br-ex with port number 15:
# ovs-ofctl show br-int
18(int-br-ex): addr:fe:b7:cb:03:c5:c1
config:
0
state:
0
speed: 0 Mbps now, 0 Mbps max
When the packet arrives on int-br-ex, an OVS flow rule inside br-int adds internal VLAN tag 2 for
provider-171 and VLAN tag 3 for provider-172 to the packet:
# ovs-ofctl dump-flows br-int
NXST_FLOW reply (xid=0x4):
cookie=0x0, duration=6770.572s, table=0, n_packets=1239,
n_bytes=127795, idle_age=106, priority=1 actions=NORMAL
cookie=0x0, duration=3181.679s, table=0, n_packets=2605,
n_bytes=246456, idle_age=0, priority=3,in_port=18,dl_vlan=172
actions=mod_vlan_vid:3,NORMAL
cookie=0x0, duration=6353.898s, table=0, n_packets=5077,
n_bytes=482582, idle_age=0, priority=3,in_port=18,dl_vlan=171
actions=mod_vlan_vid:2,NORMAL
cookie=0x0, duration=6769.391s, table=0, n_packets=22301,
n_bytes=2013101, idle_age=0, priority=2,in_port=18 actions=drop
cookie=0x0, duration=6770.463s, table=23, n_packets=0, n_bytes=0,
idle_age=6770, priority=0 actions=drop
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The second rule says a packet that arrives on int-br-ex (in_port=15) which has VLAN tag 172 in it
(dl_vlan=172), replace VLAN tag with 3 (actions=mod_vlan_vid:3,NORMAL) and forward.
The third rule says a packet that arrives on int-br-ex (in_port=15) which has VLAN tag 171 in it
(dl_vlan=171), replace VLAN tag with 2 (actions=mod_vlan_vid:2,NORMAL) and forward.
With the internal VLAN tag added to the packet, qvo-xxx accepts it and forwards it on to qvb-xx
(after stripping the VLAN tag), after which the packet then reaches the instance.
Note that the VLAN tag 2 and 3 is an example that was used on a test Compute node for the VLAN
provider networks (provider-171 and provider-172). The required configuration may be different for
your VLAN provider network, and can also be different for the same network on two different
Compute nodes.
7.2.3. Troubleshooting
Refer to the packet flow described in the section above when troubleshooting connectivity in a VLAN
provider network. In addition, review the following configuration options:
1. Verify that physical network name is used consistently. In this example, physnet1 is used
consistently while creating the network, and within the bridge_mapping configuration:
# grep bridge_mapping
/etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini
bridge_mappings = physnet1:br-ex
# neutron net-show provider-vlan171
...
| provider:physical_network | physnet1
...
2. Confirm that the network was created as external, is type vlan, and uses the correct
segmentation_id value:
# neutron net-show provider-vlan171
...
| provider:network_type
| vlan
| provider:physical_network | physnet1
| provider:segmentation_id | 171
...
|
|
|
3. Run ovs-vsctl show and verify that br-int and br-ex are connected using the patch-peer intbr-ex <→ phy-br-ex.
This connection is created while restarting neutron-openvswitch-agent, provided that the
bridge_mapping is correctly configured in
/etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini.
Recheck the bridge_mapping setting if this is not created even after restarting the service.
4. To review the flow of outgoing packets, run ovs-ofctl dump-flows br-ex and ovs-ofctl
dump-flows br-int, and verify that the flows map the internal VLAN IDs to the external VLAN ID
(segmentation_id). For incoming packets, map the external VLAN ID to the internal VLAN ID.
This flow is added by the neutron OVS agent when you spawn an instance to this network for the
first time. If this flow is not created after spawning the instance, make sure that the network is
created as vlan, is external, and that the physical_network name is correct. In addition, recheck the bridge_mapping settings.
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CHAPTER 7. CONNECT AN INSTANCE TO THE PHYSICAL NETWORK
5. Finally, re-check the ifcfg-br-ex and ifcfg-ethx configuration. Make sure that ethX is added as a
port inside br-ex, and that both of them have UP flag in the output of the ip a command.
For example, the output below shows that eth1 is a port in br-ex.
Bridge br-ex
Port phy-br-ex
Interface phy-br-ex
type: patch
options: {peer=int-br-ex}
Port "eth1"
Interface "eth1"
The command below shows that eth1 has been added as a port, and that the kernel is aware to
move all packets from the interface to the OVS bridge br-ex. This is demonstrated by the entry:
master ovs-system.
# ip a
5: eth1: mtu 1500 qdisc mq master
ovs-system state UP qlen 1000
7.3. Enable Compute metadata access
Instances connected in this way are directly attached to the provider external networks, and have
external routers configured as their default gateway; no OpenStack Networking (neutron) routers are
used. This means that neutron routers cannot be used to proxy metadata requests from instances to
the nova-metadata server, which may result in failures while running cloud-init. However, this issue
can be resolved by configuring the dhcp agent to proxy metadata requests. You can enable this
functionality in /etc/neutron/dhcp_agent.ini. For example:
enable_isolated_metadata = True
7.4. Floating IP addresses
Note that the same network can be used to allocate floating IP addresses to instances, even if they
have been added to private networks at the same time. The addresses allocated as floating IPs from
this network will be bound to the qrouter-xxx namespace on the Network node, and will perform
DNAT-SNAT to the associated private IP address. In contrast, the IP addresses allocated for direct
external network access will be bound directly inside the instance, and allow the instance to
communicate directly with external network.
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Red Hat OpenStack Platform 8 Networking Guide
CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR
OPENSTACK NETWORKING
This chapter documents the common physical switch configuration steps required for OpenStack
Networking. Vendor-specific configuration is included for the popular switch vendors, including
Cisco, Extreme Networks, and Juniper.
8.1. Planning your physical network environment
The physical network adapters in your OpenStack nodes can be expected to carry different types of
network traffic, such as instance traffic, storage data, or authentication requests. The type of traffic
these NICs will carry affects how their ports are configured on the physical switch.
As a first step, you will need to decide which physical NICs on your Compute node will carry which
types of traffic. Then, when the NIC is cabled to a physical switch port, that switch port will need to
be specially configured to allow trunked or general traffic.
For example, this diagram depicts a Compute node with two NICs, eth0 and eth1. Each NIC is
cabled to a Gigabit Ethernet port on a physical switch, with eth0 carrying instance traffic, and eth1
providing connectivity for OpenStack services:
Note
This diagram does not include any additional redundant NICs required for fault tolerance.
8.2. Configure a Cisco Catalyst switch
8.2.1. Configure trunk ports
OpenStack Networking allows instances to connect to the VLANs that already exist on your physical
network. The term trunk is used to describe a port that allows multiple VLANs to traverse through
the same port. As a result, VLANs can span across multiple switches, including virtual switches. For
example, traffic tagged as VLAN110 in the physical network can arrive at the Compute node, where
the 8021q module will direct the tagged traffic to the appropriate VLAN on the vSwitch.
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CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR OPENSTACK NETWORKING
8.2.1.1. Configure trunk ports for a Cisco Catalyst switch
If using a Cisco Catalyst switch running Cisco IOS, you might use the following configuration syntax
to allow traffic for VLANs 110 and 111 to pass through to your instances. This configuration assumes
that your physical node has an ethernet cable connected to interface GigabitEthernet1/0/12 on
the physical switch.
Note
These values are examples only. Simply copying and pasting into your switch
configuration without adjusting the values first will likely result in an unexpected outage to
something, somewhere.
interface GigabitEthernet1/0/12
description Trunk to Compute Node
spanning-tree portfast trunk
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk native vlan 1
switchport trunk allowed vlan 1,110,111
These settings are described below:
Field
Description
interface GigabitEthernet1/0/12
This is the switch port that the node’s NIC is
plugged into. This is just an example, so it is
important to first verify that you are configuring the
correct port here. You can use the show interface
command to view a list of ports.
description Trunk to Compute Node
The description that appears when listing all
interfaces using the show interface command.
Should be descriptive enough to let someone
understand which system is plugged into this port,
and what the connection’s intended function is.
spanning-tree portfast trunk
Assuming your environment uses STP, tells Port
Fast that this port is used to trunk traffic.
switchport trunk encapsulation
dot1q
Enables the 802.1q trunking standard (rather than
ISL). This will vary depending on what your switch
supports.
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Field
Description
switchport mode trunk
Configures this port as a trunk port, rather than an
access port, meaning that it will allow VLAN traffic
to pass through to the virtual switches.
switchport trunk native vlan 1
Setting a native VLAN tells the switch where to
send untagged (non-VLAN) traffic.
switchport trunk allowed vlan
1,110,111
Defines which VLANs are allowed through the
trunk.
Note
Since this port integrates with SDN switches, configuring just spanning-tree portfast might
result in a switching loop, blocking the port.
8.2.2. Configure access ports
Not all NICs on your Compute node will carry instance traffic, and so do not need to be configured to
allow multiple VLANs to pass through. These ports require only one VLAN to be configured, and
might fulfill other operational requirements, such as transporting management traffic or Block
Storage data. These ports are commonly known as access ports and usually require a simpler
configuration than trunk ports.
8.2.2.1. Configure access ports for a Cisco Catalyst switch
To continue the example from the diagram above, this example configures GigabitEthernet1/0/13
(on a Cisco Catalyst switch) as an access port for eth1. This configuration assumes that your
physical node has an ethernet cable connected to interface GigabitEthernet1/0/12 on the
physical switch.
Note
These values are examples only. Simply copying and pasting into your switch
configuration without adjusting the values first will likely result in an unexpected outage to
something, somewhere.
interface GigabitEthernet1/0/13
description Access port for Compute Node
switchport mode access
switchport access vlan 200
spanning-tree portfast
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CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR OPENSTACK NETWORKING
These settings are described below:
Field
Description
interface GigabitEthernet1/0/13
This is the switch port that the node’s NIC is
plugged into. The interface value is just an
example, so it is important to first verify that you
are configuring the correct port here. You can use
the show interface command to view a list of ports.
description Access port for
Compute Node
The description that appears when listing all
interfaces using the show interface command.
Should be descriptive enough to let someone
understand which system is plugged into this port,
and what the connection’s intended function is.
switchport mode access
Configures this port as an access port, rather than
a trunk port.
switchport access vlan 200
Configures the port to allow traffic on VLAN 200.
Your Compute node should also be configured with
an IP address from this VLAN.
spanning-tree portfast
If using STP, this tells STP not to attempt to
initialize this as a trunk, allowing for quicker port
handshakes during initial connections (such as
server reboot).
8.2.3. Configure LACP port aggregation
LACP allows you to bundle multiple physical NICs together to form a single logical channel. Also
known as 802.3ad (or bonding mode 4 in Linux), LACP creates a dynamic bond for load-balancing
and fault tolerance. LACP must be configured at both physical ends: on the physical NICs, and on
the physical switch ports.
8.2.3.1. Configure LACP on the physical NIC
1. Edit the /home/stack/network-environment.yaml file:
- type: linux_bond
name: bond1
mtu: 9000
bonding_options:{get_param: BondInterfaceOvsOptions};
members:
- type: interface
name: nic3
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Red Hat OpenStack Platform 8 Networking Guide
mtu: 9000
primary: true
- type: interface
name: nic4
mtu: 9000
2. Configure the Open vSwitch bridge to use LACP:
BondInterfaceOvsOptions:
"mode=802.3ad"
For information on configuring network bonds, see the Director Installation and Usage guide.
8.2.3.2. Configure LACP on a Cisco Catalyst switch
In this example, the Compute node has two NICs using VLAN 100:
1. Physically connect the Compute node’s two NICs to the switch (for example, ports 12 and 13).
2. Create the LACP port channel:
interface port-channel1
switchport access vlan 100
switchport mode access
spanning-tree portfast disable
spanning-tree bpduguard disable
spanning-tree guard root
3. Configure switch ports 12 (Gi1/0/12) and 13 (Gi1/0/13):
sw01# config t
Enter configuration commands, one per line.
End with CNTL/Z.
sw01(config) interface GigabitEthernet1/0/12
switchport access vlan 100
switchport mode access
speed 1000
duplex full
channel-group 10 mode active
channel-protocol lacp
interface GigabitEthernet1/0/13
switchport access vlan 100
switchport mode access
speed 1000
duplex full
channel-group 10 mode active
channel-protocol lacp
4. Review your new port channel. The resulting output lists the new port-channel Po1, with member
ports Gi1/0/12 and Gi1/0/13:
sw01# show etherchannel summary
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CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR OPENSTACK NETWORKING
Number of channel-groups in use: 1
Number of aggregators:
1
Group Port-channel Protocol
Ports
------+-------------+-----------+---------------------------------------------1
Po1(SD)
LACP
Gi1/0/12(D) Gi1/0/13(D)
Note
Remember to apply your changes by copying the running-config to the startup-config:
copy running-config startup-config.
8.2.4. Configure MTU settings
Certain types of network traffic might require that you adjust your MTU size. For example, jumbo
frames (9000 bytes) might be suggested for certain NFS or iSCSI traffic.
Note
MTU settings must be changed from end-to-end (on all hops that the traffic is expected to
pass through), including any virtual switches. For information on changing the MTU in your
OpenStack environment, see Chapter 9, Configure MTU Settings.
8.2.4.1. Configure MTU settings on a Cisco Catalyst switch
This example enables jumbo frames on your Cisco Catalyst 3750 switch.
1. Review the current MTU settings:
sw01# show system mtu
System MTU size is 1600 bytes
System Jumbo MTU size is 1600 bytes
System Alternate MTU size is 1600 bytes
Routing MTU size is 1600 bytes
2. MTU settings are changed switch-wide on 3750 switches, and not for individual interfaces. This
command configures the switch to use jumbo frames of 9000 bytes:
sw01# config t
Enter configuration commands, one per line.
End with CNTL/Z.
sw01(config)# system mtu jumbo 9000
Changes to the system jumbo MTU will not take effect until the next
reload is done
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Red Hat OpenStack Platform 8 Networking Guide
Note
Remember to save your changes by copying the running-config to the startup-config: copy
running-config startup-config.
3. When possible, reload the switch to apply the change. This will result in a network outage for any
devices that are dependent on the switch.
sw01# reload
Proceed with reload? [confirm]
4. When the switch has completed its reload operation, confirm the new jumbo MTU size:
sw01# show system mtu
System MTU size is 1600 bytes
System Jumbo MTU size is 9000 bytes
System Alternate MTU size is 1600 bytes
Routing MTU size is 1600 bytes
8.2.5. Configure LLDP discovery
The ironic-python-agent service listens for LLDP packets from connected switches. The
collected information can include the switch name, port details, and available VLANs. Similar to
Cisco Discovery Protocol (CDP), LLDP assists with the discovery of physical hardware during
director’s introspection process.
8.2.5.1. Configure LLDP on a Cisco Catalyst switch
1. Use lldp run to enable LLDP globally on your Cisco Catalyst switch:
sw01# config t
Enter configuration commands, one per line.
End with CNTL/Z.
sw01(config)# lldp run
2. View any neighboring LLDP-compatible devices:
sw01# show lldp neighbor
Capability codes:
(R) Router, (B) Bridge, (T) Telephone, (C) DOCSIS Cable Device
(W) WLAN Access Point, (P) Repeater, (S) Station, (O) Other
Device ID
DEP42037061562G3
422037061562G3:P1
Local Intf
Gi1/0/11
Total entries displayed: 1
66
Hold-time
180
Capability
B,T
Port ID
CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR OPENSTACK NETWORKING
Note
Remember to save your changes by copying the running-config to the startup-config: copy
running-config startup-config.
8.3. Configure a Cisco Nexus switch
8.3.1. Configure trunk ports
OpenStack Networking allows instances to connect to the VLANs that already exist on your physical
network. The term trunk is used to describe a port that allows multiple VLANs to traverse through
the same port. As a result, VLANs can span across multiple switches, including virtual switches. For
example, traffic tagged as VLAN110 in the physical network can arrive at the Compute node, where
the 8021q module will direct the tagged traffic to the appropriate VLAN on the vSwitch.
8.3.1.1. Configure trunk ports for a Cisco Nexus switch
If using a Cisco Nexus you might use the following configuration syntax to allow traffic for VLANs
110 and 111 to pass through to your instances. This configuration assumes that your physical node
has an ethernet cable connected to interface Ethernet1/12 on the physical switch.
Note
These values are examples only. Simply copying and pasting into your switch
configuration without adjusting the values first will likely result in an unexpected outage to
something, somewhere.
interface Ethernet1/12
description Trunk to Compute Node
switchport mode trunk
switchport trunk allowed vlan 1,110,111
switchport trunk native vlan 1
end
8.3.2. Configure access ports
Not all NICs on your Compute node will carry instance traffic, and so do not need to be configured to
allow multiple VLANs to pass through. These ports require only one VLAN to be configured, and
might fulfill other operational requirements, such as transporting management traffic or Block
Storage data. These ports are commonly known as access ports and usually require a simpler
configuration than trunk ports.
8.3.2.1. Configure access ports for a Cisco Nexus switch
To continue the example from the diagram above, this example configures Ethernet1/13 (on a Cisco
Nexus switch) as an access port for eth1. This configuration assumes that your physical node has
an ethernet cable connected to interface Ethernet1/13 on the physical switch.
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Red Hat OpenStack Platform 8 Networking Guide
Note
These values are examples only. Simply copying and pasting into your switch
configuration without adjusting the values first will likely result in an unexpected outage to
something, somewhere.
interface Ethernet1/13
description Access port for Compute Node
switchport mode access
switchport access vlan 200
8.3.3. Configure LACP port aggregation
LACP allows you to bundle multiple physical NICs together to form a single logical channel. Also
known as 802.3ad (or bonding mode 4 in Linux), LACP creates a dynamic bond for load-balancing
and fault tolerance. LACP must be configured at both physical ends: on the physical NICs, and on
the physical switch ports.
8.3.3.1. Configure LACP on the physical NIC
1. Edit the /home/stack/network-environment.yaml file:
- type: linux_bond
name: bond1
mtu: 9000
bonding_options:{get_param: BondInterfaceOvsOptions};
members:
- type: interface
name: nic3
mtu: 9000
primary: true
- type: interface
name: nic4
mtu: 9000
2. Configure the Open vSwitch bridge to use LACP:
BondInterfaceOvsOptions:
"mode=802.3ad"
For information on configuring network bonds, see the Director Installation and Usage guide.
8.3.3.2. Configure LACP on a Cisco Nexus switch
In this example, the Compute node has two NICs using VLAN 100:
1. Physically connect the Compute node’s two NICs to the switch (for example, ports 12 and 13).
2. Confirm that LACP is enabled:
(config)# show feature | include lacp
lacp
1
enabled
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CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR OPENSTACK NETWORKING
3. Configure ports 1/12 and 1/13 as access ports, and as members of a channel group:
interface Ethernet1/13
description Access port for Compute Node
switchport mode access
switchport access vlan 200
channel-group 10 mode active
interface Ethernet1/13
description Access port for Compute Node
switchport mode access
switchport access vlan 200
channel-group 10 mode active
8.3.4. Configure MTU settings
Certain types of network traffic might require that you adjust your MTU size. For example, jumbo
frames (9000 bytes) might be suggested for certain NFS or iSCSI traffic.
Note
MTU settings must be changed from end-to-end (on all hops that the traffic is expected to
pass through), including any virtual switches. For information on changing the MTU in your
OpenStack environment, see Chapter 9, Configure MTU Settings.
8.3.4.1. Configure MTU settings on a Cisco Nexus 7000 switch
MTU settings can be applied to a single interface on 7000-series switches. These commands
configure interface 1/12 to use jumbo frames of 9000 bytes:
interface ethernet 1/12
mtu 9216
exit
8.3.5. Configure LLDP discovery
The ironic-python-agent service listens for LLDP packets from connected switches. The
collected information can include the switch name, port details, and available VLANs. Similar to
Cisco Discovery Protocol (CDP), LLDP assists with the discovery of physical hardware during
director’s introspection process.
8.3.5.1. Configure LLDP on a Cisco Nexus 7000 switch
LLDP can be enabled for individual interfaces on Cisco Nexus 7000-series switches:
interface ethernet 1/12
lldp transmit
lldp receive
interface ethernet 1/13
lldp transmit
lldp receive
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Red Hat OpenStack Platform 8 Networking Guide
Note
Remember to save your changes by copying the running-config to the startup-config: copy
running-config startup-config.
8.4. Configure a Cumulus Linux switch
8.4.1. Configure trunk ports
OpenStack Networking allows instances to connect to the VLANs that already exist on your physical
network. The term trunk is used to describe a port that allows multiple VLANs to traverse through
the same port. As a result, VLANs can span across multiple switches, including virtual switches. For
example, traffic tagged as VLAN110 in the physical network can arrive at the Compute node, where
the 8021q module will direct the tagged traffic to the appropriate VLAN on the vSwitch.
8.4.1.1. Configure trunk ports for a Cumulus Linux switch
If using a Cumulus Linux switch, you might use the following configuration syntax to allow traffic for
VLANs 100 and 200 to pass through to your instances. This configuration assumes that your
physical node has transceivers connected to switch ports swp1 and swp2 on the physical switch.
Note
These values are examples only. Simply copying and pasting into your switch
configuration without adjusting the values first will likely result in an unexpected outage to
something, somewhere.
auto bridge
iface bridge
bridge-vlan-aware yes
bridge-ports glob swp1-2
bridge-vids 100 200
8.4.2. Configure access ports
Not all NICs on your Compute node will carry instance traffic, and so do not need to be configured to
allow multiple VLANs to pass through. These ports require only one VLAN to be configured, and
might fulfill other operational requirements, such as transporting management traffic or Block
Storage data. These ports are commonly known as access ports and usually require a simpler
configuration than trunk ports.
8.4.2.1. Configuring access ports for a Cumulus Linux switch
To continue the example from the diagram above, this example configures swp1 (on a Cumulus
Linux switch) as an access port. This configuration assumes that your physical node has an ethernet
cable connected to the interface on the physical switch. Cumulus Linux switches use eth for
management interfaces and swp for access/trunk ports.
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CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR OPENSTACK NETWORKING
Note
These values are examples only. Simply copying and pasting into your switch
configuration without adjusting the values first will likely result in an unexpected outage to
something, somewhere.
auto bridge
iface bridge
bridge-vlan-aware yes
bridge-ports glob swp1-2
bridge-vids 100 200
auto swp1
iface swp1
bridge-access 100
auto swp2
iface swp2
bridge-access 200
8.4.3. Configure LACP port aggregation
LACP allows you to bundle multiple physical NICs together to form a single logical channel. Also
known as 802.3ad (or bonding mode 4 in Linux), LACP creates a dynamic bond for load-balancing
and fault tolerance. LACP must be configured at both physical ends: on the physical NICs, and on
the physical switch ports.
8.4.3.1. Configure LACP on the physical NIC
There is no need to configure the physical NIC in Cumulus Linux.
8.4.3.2. Configure LACP on a Cumulus Linux switch
To configure the bond, edit /etc/network/interfaces and add a stanza for bond0:
auto bond0
iface bond0
address 10.0.0.1/30
bond-slaves swp1 swp2 swp3 swp4
Note
Remember to apply your changes by reloading the updated configuration: sudo
ifreload -a
8.4.4. Configure MTU settings
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Red Hat OpenStack Platform 8 Networking Guide
Certain types of network traffic might require that you adjust your MTU size. For example, jumbo
frames (9000 bytes) might be suggested for certain NFS or iSCSI traffic.
Note
MTU settings must be changed from end-to-end (on all hops that the traffic is expected to
pass through), including any virtual switches. For information on changing the MTU in your
OpenStack environment, see Chapter 9, Configure MTU Settings.
8.4.4.1. Configure MTU settings on a Cumulus Linux switch
This example enables jumbo frames on your Cumulus Linux switch.
auto swp1
iface swp1
mtu 9000
Remember to apply your changes by reloading the updated configuration: sudo ifreload -a
8.4.5. Configure LLDP discovery
By default, the LLDP service, lldpd, runs as a daemon and starts when the switch boots.
To view all LLDP neighbors on all ports/interfaces:
cumulus@switch$ netshow lldp
Local Port Speed Mode
---------- ----------eth0
10G
Mgmt
10.0.1.11/24
swp51
10G
Interface/L3
10.0.0.11/32
swp52
10G
Interface/L
10.0.0.11/32
Remote Port
----- ----====
swp6
Remote Host Summary
----------- -------mgmt-sw
IP:
====
swp1
spine01
IP:
====
swp1
spine02
IP:
8.5. Configure an Extreme Networks EXOS switch
8.5.1. Configure trunk ports
OpenStack Networking allows instances to connect to the VLANs that already exist on your physical
network. The term trunk is used to describe a port that allows multiple VLANs to traverse through
the same port. As a result, VLANs can span across multiple switches, including virtual switches. For
example, traffic tagged as VLAN110 in the physical network can arrive at the Compute node, where
the 8021q module will direct the tagged traffic to the appropriate VLAN on the vSwitch.
8.5.1.1. Configure trunk ports on an Extreme Networks EXOS switch
If using an X-670 series switch, you might refer to the following example to allow traffic for VLANs
110 and 111 to pass through to your instances. This configuration assumes that your physical node
has an ethernet cable connected to interface 24 on the physical switch. In this example, DATA and
MNGT are the VLAN names.
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CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR OPENSTACK NETWORKING
Note
These values are examples only. Simply copying and pasting into your switch
configuration without adjusting the values first will likely result in an unexpected outage to
something, somewhere.
#create vlan DATA tag 110
#create vlan MNGT tag 111
#configure vlan DATA add ports 24 tagged
#configure vlan MNGT add ports 24 tagged
8.5.2. Configure access ports
Not all NICs on your Compute node will carry instance traffic, and so do not need to be configured to
allow multiple VLANs to pass through. These ports require only one VLAN to be configured, and
might fulfill other operational requirements, such as transporting management traffic or Block
Storage data. These ports are commonly known as access ports and usually require a simpler
configuration than trunk ports.
8.5.2.1. Configure access ports for an Extreme Networks EXOS switch
To continue the example from the diagram above, this example configures 10 (on a Extreme
Networks X-670 series switch) as an access port for eth1. you might use the following configuration
to allow traffic for VLANs 110 and 111 to pass through to your instances. This configuration
assumes that your physical node has an ethernet cable connected to interface 10 on the physical
switch.
Note
These values are examples only. Simply copying and pasting into your switch
configuration without adjusting the values first will likely result in an unexpected outage to
something, somewhere.
create vlan VLANNAME tag NUMBER
configure vlan Default delete ports PORTSTRING
configure vlan VLANNAME add ports PORTSTRING untagged
For example:
#create vlan DATA tag 110
#configure vlan Default delete ports 10
#configure vlan DATA add ports 10 untagged
8.5.3. Configure LACP port aggregation
LACP allows you to bundle multiple physical NICs together to form a single logical channel. Also
known as 802.3ad (or bonding mode 4 in Linux), LACP creates a dynamic bond for load-balancing
and fault tolerance. LACP must be configured at both physical ends: on the physical NICs, and on
the physical switch ports.
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8.5.3.1. Configure LACP on the physical NIC
1. Edit the /home/stack/network-environment.yaml file:
- type: linux_bond
name: bond1
mtu: 9000
bonding_options:{get_param: BondInterfaceOvsOptions};
members:
- type: interface
name: nic3
mtu: 9000
primary: true
- type: interface
name: nic4
mtu: 9000
2. Configure the Open vSwitch bridge to use LACP:
BondInterfaceOvsOptions:
"mode=802.3ad"
For information on configuring network bonds, see the Director Installation and Usage guide.
8.5.3.2. Configure LACP on an Extreme Networks EXOS switch
In this example, the Compute node has two NICs using VLAN 100:
enable sharing MASTERPORT grouping ALL_LAG_PORTS lacp
configure vlan VLANNAME add ports PORTSTRING tagged
For example:
#enable sharing 11 grouping 11,12 lacp
#configure vlan DATA add port 11 untagged
8.5.4. Configure MTU settings
Certain types of network traffic might require that you adjust your MTU size. For example, jumbo
frames (9000 bytes) might be suggested for certain NFS or iSCSI traffic.
Note
MTU settings must be changed from end-to-end (on all hops that the traffic is expected to
pass through), including any virtual switches. For information on changing the MTU in your
OpenStack environment, see Chapter 9, Configure MTU Settings.
8.5.4.1. Configure MTU settings on an Extreme Networks EXOS switch
The example enables jumbo frames on any Extreme Networks EXOS switch, and supports
forwarding IP packets with 9000 bytes:
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CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR OPENSTACK NETWORKING
enable jumbo-frame ports PORTSTRING
configure ip-mtu 9000 vlan VLANNAME
For example:
# enable jumbo-frame ports 11
# configure ip-mtu 9000 vlan DATA
8.5.5. Configure LLDP discovery
The ironic-python-agent service listens for LLDP packets from connected switches. The
collected information can include the switch name, port details, and available VLANs. Similar to
Cisco Discovery Protocol (CDP), LLDP assists with the discovery of physical hardware during
director’s introspection process.
8.5.5.1. Configure LLDP settings on an Extreme Networks EXOS switch
The example allows configuring LLDP settings on any Extreme Networks EXOS switch. In this
example, 11 represents the port string:
enable lldp ports 11
8.6. Configure a Juniper EX Series switch
8.6.1. Configure trunk ports
OpenStack Networking allows instances to connect to the VLANs that already exist on your physical
network. The term trunk is used to describe a port that allows multiple VLANs to traverse through
the same port. As a result, VLANs can span across multiple switches, including virtual switches. For
example, traffic tagged as VLAN110 in the physical network can arrive at the Compute node, where
the 8021q module will direct the tagged traffic to the appropriate VLAN on the vSwitch.
8.6.1.1. Configure trunk ports on the Juniper EX Series switch
If using a Juniper EX series switch running Juniper JunOS, you might use the following
configuration to allow traffic for VLANs 110 and 111 to pass through to your instances. This
configuration assumes that your physical node has an ethernet cable connected to interface ge1/0/12 on the physical switch.
Note
These values are examples only. Simply copying and pasting into your switch
configuration without adjusting the values first will likely result in an unexpected outage to
something, somewhere.
ge-1/0/12 {
description Trunk to Compute Node;
unit 0 {
family ethernet-switching {
port-mode trunk;
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Red Hat OpenStack Platform 8 Networking Guide
vlan {
members [110 111];
}
native-vlan-id 1;
}
}
}
8.6.2. Configure access ports
Not all NICs on your Compute node will carry instance traffic, and so do not need to be configured to
allow multiple VLANs to pass through. These ports require only one VLAN to be configured, and
might fulfill other operational requirements, such as transporting management traffic or Block
Storage data. These ports are commonly known as access ports and usually require a simpler
configuration than trunk ports.
8.6.2.1. Configure access ports for a Juniper EX Series switch
To continue the example from the diagram above, this example configures ge-1/0/13 (on a Juniper
EX series switch) as an access port for eth1. This configuration assumes that your physical node
has an ethernet cable connected to interface ge-1/0/13 on the physical switch.
Note
These values are examples only. Simply copying and pasting into your switch
configuration without adjusting the values first will likely result in an unexpected outage to
something, somewhere.
ge-1/0/13 {
description Access port for Compute Node
unit 0 {
family ethernet-switching {
port-mode access;
vlan {
members 200;
}
native-vlan-id 1;
}
}
}
8.6.3. Configure LACP port aggregation
LACP allows you to bundle multiple physical NICs together to form a single logical channel. Also
known as 802.3ad (or bonding mode 4 in Linux), LACP creates a dynamic bond for load-balancing
and fault tolerance. LACP must be configured at both physical ends: on the physical NICs, and on
the physical switch ports.
8.6.3.1. Configure LACP on the physical NIC
1. Edit the /home/stack/network-environment.yaml file:
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CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR OPENSTACK NETWORKING
- type: linux_bond
name: bond1
mtu: 9000
bonding_options:{get_param: BondInterfaceOvsOptions};
members:
- type: interface
name: nic3
mtu: 9000
primary: true
- type: interface
name: nic4
mtu: 9000
2. Configure the Open vSwitch bridge to use LACP:
BondInterfaceOvsOptions:
"mode=802.3ad"
For information on configuring network bonds, see the Director Installation and Usage guide.
8.6.3.2. Configure LACP on a Juniper EX Series switch
In this example, the Compute node has two NICs using VLAN 100:
1. Physically connect the Compute node’s two NICs to the switch (for example, ports 12 and 13).
2. Create the port aggregate:
chassis {
aggregated-devices {
ethernet {
device-count 1;
}
}
}
3. Configure switch ports 12 (ge-1/0/12) and 13 (ge-1/0/13) to join the port aggregate ae1:
interfaces {
ge-1/0/12 {
gigether-options {
802.3ad ae1;
}
}
ge-1/0/13 {
gigether-options {
802.3ad ae1;
}
}
}
4. Enable LACP on port aggregate ae1:
interfaces {
ae1 {
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Red Hat OpenStack Platform 8 Networking Guide
aggregated-ether-options {
lacp {
active;
}
}
}
}
5. Add aggregate ae1 to VLAN 100:
interfaces {
ae1 {
vlan-tagging;
unit 100 {
vlan-id 100;
}
}
}
6. Review your new port channel. The resulting output lists the new port aggregate ae1 with
member ports ge-1/0/12 and ge-1/0/13:
> show lacp statistics interfaces ae1
Aggregated interface: ae1
LACP Statistics: LACP Rx LACP Tx Unknown Rx Illegal Rx
ge-1/0/12 0 0 0 0
ge-1/0/13 0 0 0 0
Note
Remember to apply your changes by running the commit command.
8.6.4. Configure MTU settings
Certain types of network traffic might require that you adjust your MTU size. For example, jumbo
frames (9000 bytes) might be suggested for certain NFS or iSCSI traffic.
Note
MTU settings must be changed from end-to-end (on all hops that the traffic is expected to
pass through), including any virtual switches. For information on changing the MTU in your
OpenStack environment, see Chapter 9, Configure MTU Settings.
8.6.4.1. Configure MTU settings on a Juniper EX Series switch
This example enables jumbo frames on your Juniper EX4200 switch.
1. For Juniper EX series switches, MTU settings are set for individual interfaces. These commands
configure jumbo frames on the ge-1/0/14 and ge-1/0/15 ports:
set interfaces ge-1/0/14 mtu 9216
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CHAPTER 8. CONFIGURE PHYSICAL SWITCHES FOR OPENSTACK NETWORKING
set interfaces ge-1/0/15 mtu 9216
Note
Remember to save your changes by running the commit command.
2. If using a LACP aggregate, you will need to set the MTU size there, and not on the member NICs.
For example, this setting configures the MTU size for the ae1 aggregate:
set interfaces ae1 mtu 9200
8.6.5. Configure LLDP discovery
The ironic-python-agent service listens for LLDP packets from connected switches. The
collected information can include the switch name, port details, and available VLANs. Similar to
Cisco Discovery Protocol (CDP), LLDP assists with the discovery of physical hardware during
director’s introspection process.
8.6.5.1. Configure LLDP on a Juniper EX Series switch
You can enable LLDP globally for all interfaces, or just for individual ones:
1. For example, to enable LLDP globally on your Juniper EX 4200 switch:
lldp {
interface all{
enable;
}
}
}
2. Or, enable LLDP just for the single interface ge-1/0/14:
lldp {
interface ge-1/0/14{
enable;
}
}
}
Note
Remember to apply your changes by running the commit command.
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Red Hat OpenStack Platform 8 Networking Guide
PART II. ADVANCED CONFIGURATION
Contains cookbook-style scenarios for advanced OpenStack Networking features.
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CHAPTER 9. CONFIGURE MTU SETTINGS
CHAPTER 9. CONFIGURE MTU SETTINGS
9.1. MTU overview
In Red Hat OpenStack Platform 8 (liberty), OpenStack Networking has the ability to calculate the
largest possible MTU size that can safely be applied to instances. The MTU value specifies the
maximum amount of data a single network packet is able to transfer; this number is variable
depending on the most appropriate size for the application. For example, NFS shares might require
a different MTU size to that of a VoIP application.
Note
For Red Hat OpenStack Platform 8 (liberty), OpenStack Networking is able to calculate the
largest possible MTU value, which can then be viewed using the neutron net-show
command. The required MTU value can be advertised to DHCPv4 clients for automatic
configuration, if supported by the instance.
MTU settings need to be set consistently from end-to-end in order to work properly. This means that
the MTU setting needs to be the same size at every point the packet passes through, including the
VM itself, the virtual network infrastructure, the physical network, and the destination server itself.
For example, the red dots in the following diagram indicate the various points where an MTU value
would need to be adjusted for traffic between an instance and a physical server. Every interface that
handles network traffic will need to have its MTU value changed to accommodate packets of a
particular MTU size. This will be required if traffic is expected to travel from the instance
192.168.200.15 through to the physical server 10.20.15.25 and avoid becoming fragmented in the
process:
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Inconsistent MTU values can result in several network issues, the most common being slow
network performance. Such issues are problematic to troubleshoot, since every possible network
point needs to be identified and examined to ensure it has the correct MTU value set.
9.1.1. Configure MTU advertisement
MTU advertisement eases the MTU configuration process by moving MTU settings into the realm of
automated DHCP configuration. As a result, the optimal MTU size is then advertised to instances
using DHCPv4. Enable MTU advertisement in /etc/neutron/neutron.conf:
advertise_mtu = True
When set, the tenant network’s configured MTU option is advertised to instances using DHCPv4.
Note
Not all DHCPv4 clients support the automatic configuration of MTU values.
9.1.2. Configure tenant networks
With Red Hat OpenStack Platform 8 director, you can use a single parameter in the network
environment file to define the default MTU for all tenant networks. This will make it easier to align
your configuration with the physical MTU:
NeutronTenantMtu - Sets the MTU size of the virtual Ethernet device. If using VXLAN/GRE
tunneling, then this should be at least 50 bytes smaller than the MTU operating on the physical
network. By default, the value is 1400.
9.1.3. Configure MTU Settings in Director
This example demonstrates how to set the MTU using the NIC config templates. The MTU needs to
be set on the bridge, bond (if applicable), interface(s), and VLAN(s):
type: ovs_bridge
name: br-isolated
use_dhcp: false
mtu: 9000
# <--- Set MTU
members:
type: ovs_bond
name: bond1
mtu: 9000
# <--- Set MTU
ovs_options: {get_param: BondInterfaceOvsOptions}
members:
type: interface
name: ens15f0
mtu: 9000
# <--- Set MTU
primary: true
type: interface
name: enp131s0f0
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CHAPTER 9. CONFIGURE MTU SETTINGS
mtu: 9000
# <--- Set MTU
type: vlan
device: bond1
vlan_id: {get_param: InternalApiNetworkVlanID}
mtu: 9000
# <--- Set MTU
addresses:
ip_netmask: {get_param: InternalApiIpSubnet}
type: vlan
device: bond1
mtu: 9000
# <--- Set MTU
vlan_id: {get_param: TenantNetworkVlanID}
addresses:
ip_netmask: {get_param: TenantIpSubnet}
9.1.4. Review the resulting MTU calculation
View the calculated MTU value. This result is the calculation of the largest possible MTU value that
can be used by instances. You can then proceed by configuring this value on all interfaces involved
in the path of network traffic.
# neutron net-show
Note
At present, it is recommended to lower the MTU value inside instances to a value smaller
than 1500 bytes (for example: 1450 bytes). This smaller value accounts for the additional
headers that Open vSwitch adds for routing purposes.
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Red Hat OpenStack Platform 8 Networking Guide
CHAPTER 10. CONFIGURE QUALITY-OF-SERVICE (QOS)
Red Hat OpenStack Platform 8 introduces support for network quality-of-service (QoS) policies.
These policies allow OpenStack administrators to offer varying service levels by applying rate limits
to egress traffic for instances. As a result of implementing a QoS policy, any traffic that exceeds the
specified rate is consequently dropped.
10.1. QoS Policy Scope
QoS policies are applied to individual ports, or to a particular tenant network, where all ports will
inherit the policy.
10.2. QoS Policy Management
QoS policies can be dynamically applied, modified, or removed. This example manually creates a
bandwidth limiting rule and applies it to a port.
1. Review the list of tenants and determine the id of where you need to create QoS policy:
# keystone tenant-list
+----------------------------------+--------------------+--------+
|
id
|
name
|
enabled |
+----------------------------------+--------------------+--------+
| 35c6f4eb8bc24455a1df527760c091f5 |
admin
|
True
|
| d602b03dcc324dd483d37163388b2021 |
demo
|
True
|
| 74b64ba4eb3e4f08a8819454b667d4f6 |
services
|
True
|
+----------------------------------+--------------------+--------+
2. Create a QoS policy named bw-limiter in the admin tenant:
# neutron qos-policy-create --tenant-id
35c6f4eb8bc24455a1df527760c091f5 'bw-limiter'
3. Configure the policing rules for the bw-limiter policy:
# neutron qos-bandwidth-limit-rule-create bw-limiter --max_kbps
3000 --max_burst_kbps 300
4. Configure a neutron port to apply the bw-limiter policy:
# neutron port-update --qos-policy bw-limiter
5. Review the QoS rule. For example:
# neutron qos-rule-show 9be535c3-daa2-4d7b-88ea-e8de16
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CHAPTER 10. CONFIGURE QUALITY-OF-SERVICE (QOS)
+-------------------+---------------------------------+
| Field
| Value
|
+-------------------+---------------------------------+
| id
| 9be535c3-daa2-4d7b-88ea-e8de16 |
| rule_type
| bandwidth_limit
|
| description
|
|
| max_kbps
| 3000
|
| max_burst_kbps
| 300
|
+-------------------+---------------------------------+
These values allow you to configure the policing algorithm accordingly:
max_kbps - the maximum rate (in Kbps) that the instance is allowed to send.
max_burst_kbps - the maximum amount of data (in Kbps) that this interface can send beyond
the policing rate.
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Red Hat OpenStack Platform 8 Networking Guide
CHAPTER 11. CONFIGURE BRIDGE MAPPINGS
This chapter describes how to configure bridge mappings in Red Hat OpenStack Platform.
11.1. What are bridge mappings used for?
Bridge mappings allow provider network traffic to reach the physical network. Traffic leaves the
provider network from the router’s qg-xxx interface and arrives at br-int. A veth pair between br-int
and br-ex then allows the traffic to pass through the bridge of the provider network and out to the
physical network.
11.1.1. Configure bridge mappings
Below is an example of a veth pair between br-int and br-ex:
int-br-ex <-> phy-br-ex
This connection is configured in the bridge_mappings setting. For example:
bridge_mappings = physnet1:br-ex,physnet2:br-ex2
Note
If the bridge_mapping entry is missing, no network connection exists, and communication
to external networks will not work.
This configuration’s first entry creates a connection between br-int and br-ex using patch peer
cable. The second entry creates a patch peer for br-ex2.
11.1.2. Configure the controller node
The bridge_mappings configuration must correlate with that of the network_vlan_ranges option
on the controller node. For the example given above, the controller node is configured as follows:
network_vlan_ranges = physnet1,physnet2
These values create the provider networks that represent the corresponding external networks; the
external networks are then connected to the tenant networks via router interfaces. As a result, it is
necessary to configure bridge_mappings on the network node on which the router is scheduled.
This means that the router traffic is able to egress using the correct physical network, as
represented by the provider network (for example: physnet1).
11.1.3. Traffic flow
In addition to creating the connection, this setting also configures the OVS flow in br-int and br-ex to
allow the network traffic to traverse to and from the external network. Each external network is
represented by an internal VLAN id, which is tagged to the router’s qg-xxx port. When a packet
reaches phy-br-ex, the br-ex port strips the VLAN tag and moves the packet to the physical
interface and then to the external network. The return packet from external network arrives on br-ex
and is moved to br-int using phy-br-ex <→ int-br-ex. When the packet reaches int-br-ex, another
flow in br-int adds internal vlan tag to the packet. This allows the packet to be accepted by qg-xxx.
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CHAPTER 11. CONFIGURE BRIDGE MAPPINGS
11.2. Maintaining Bridge Mappings
After removing any mappings, a subsequent patch-port cleanup is required. This action ensures that
the bridge configuration is cleared of erroneous entries, with two options available for performing
this task:
Manual port cleanup - requires careful removal of the superfluous ports. No outage is required to
network connectivity.
Automated port cleanup using neutron-ovs-cleanup - performs an automated cleanup, but
requires an outage, and requires that the necessary mappings be re-added. Choose this option if
you don’t mind having an outage to network connectivity.
Examples are given below for each of these two options:
11.2.1. Manual port cleanup
The manual port cleanup process removes unneeded ports, and doesn’t require a system outage.
You can identify these ports by their naming convention: in br-$external_bridge they are named as
"phy-"$external_bridge and in br-int they are named "int-"$external_bridge.
This example procedure removes a bridge from bridge_mappings, and cleans up the corresponding
ports. 1. Edit ovs_neutron_plugin.ini and remove the entry for physnet2:br-ex2 from
bridge_mappings:
bridge_mappings = physnet1:br-ex,physnet2:br-ex2
Remove the entry for physnet2:br-ex2. The resulting bridge_mappings resembles this:
bridge_mappings = physnet1:br-ex
2. Use ovs-vsctl to remove the patch ports associated with the removed physnet2:br-ex2 entry:
# ovs-vsctl del-port br-ex2 phy-br-ex2
# ovs-vsctl del-port br-int int-br-ex2
Note
If the entire bridge_mappings entry is removed or commented out, cleanup commands
will need to be run for each entry,
2. Restart neutron-openvswitch-agent:
# service neutron-openvswitch-agent restart
11.2.2. Automated port cleanup using ‘neutron-ovs-cleanup’
This action is performed using the neutron-ovs-cleanup command combined with the -ovs_all_ports flag. Restart the neutron services or the entire node to then restore the bridges back
to their normal working state. This process requires a total networking outage.
The neutron-ovs-cleanup command unplugs all ports (instances, qdhcp/qrouter, among others)
from all OVS bridges. Using the flag --ovs_all_ports results in removing all ports from br-int,
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Red Hat OpenStack Platform 8 Networking Guide
cleaning up tunnel ends from br-tun, and patch ports from bridge to bridge. In addition, the physical
interfaces (such as eth0, eth1) are removed from the bridges (such as br-ex, br-ex2). This will result
in lost connectivity to instances until the ports are manually re-added using ovs-vsctl:
# ovs-vsctl add-port br-ex eth1
11.2.2.1. Example usage of neutron-ovs-cleanup :
1. Make a backup of your bridge_mapping entries as found in ovs_neutron_plugin.ini.
2. Run neutron-ovs-cleanup with the --ovs_all_ports flag. Note that this step will result in a total
networking outage.
# /usr/bin/neutron-ovs-cleanup
--config-file /usr/share/neutron/neutron-dist.conf
--config-file /etc/neutron/neutron.conf
--config-file /etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini
--log-file /var/log/neutron/ovs-cleanup.log --ovs_all_ports
3. Restart these OpenStack Networking services:
# systemctl restart neutron-openvswitch-agent
# systemctl restart neutron-l3-agent.service
# systemctl restart neutron-dhcp-agent.service
4. Restore connectivity by re-adding the bridge_mapping entries to ovs_neutron_plugin.ini.
5. Restart the neutron-openvswitch-agent service:
# systemctl restart neutron-openvswitch-agent
Note
When the OVS agent restarts, it doesn’t touch any connections which are not present in
bridge_mappings. So if you have br-int connected to br-ex2, and br-ex2 has some
flows on it, removing it from the bridge_mappings configuration (or commenting it out
entirely) won’t disconnect the two bridges, no matter what you do (whether restarting the
service, or the node).
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CHAPTER 12. CONFIGURE RBAC
CHAPTER 12. CONFIGURE RBAC
Role-based Access Control (RBAC) policies in OpenStack Networking allows granular control over
shared neutron networks. Previously, networks were shared either with all tenants, or not at all.
OpenStack Networking now uses a RBAC table to control sharing of neutron networks between
tenants, allowing an administrator to control which tenants are granted permission to attach
instances to a network.
As a result, cloud administrators can remove the ability for some tenants to create networks, and
can instead allow them to attach to pre-existing networks that correspond to their project.
12.1. Create a new RBAC policy
This example procedure demonstrates how to use a RBAC policy to grant a tenant access to a
shared network.
1. View the list of available networks:
# neutron net-list
+--------------------------------------+-------------+-----------------------------------------------------+
| id
| name
| subnets
|
+--------------------------------------+-------------+-----------------------------------------------------+
| 7a7974fe-3b34-4538-b413-d22b985f26e1 | public
| 7de0811f86ed-4e1b-bc3c-fd2459d0db9d
|
| 6e437ff0-d20f-4483-b627-c3749399bdca | web-servers | fa2732451eff-4830-b40c-57eaeac9b904 192.168.10.0/24 |
| 1a744cc9-c2b2-4cfc-b06d-a10af5dc8334 | private
| 5196d7746bd2-4f5d-9c24-a4d1c8987f10 10.0.0.0/24
|
+--------------------------------------+-------------+-----------------------------------------------------+
2. View the list of tenants:
# keystone tenant-list
+----------------------------------+-------------+---------+
|
id
|
name
| enabled |
+----------------------------------+-------------+---------+
| 4be7697a4258449a9677adb0fbb71e21 |
admin
|
True |
| 09ac16ac50634b08a689c1526a34bb82 |
demo
|
True |
| c717f263785d4679b16a122516247deb | engineering |
True |
| e8549caaf5bf4bd9b5618622e7c21c97 |
services |
True |
+----------------------------------+-------------+---------+
3. Create a RBAC for the web-servers network that grants access to the engineering tenant
(c717f263785d4679b16a122516247deb):
# neutron rbac-create 6e437ff0-d20f-4483-b627-c3749399bdca --type
network --target-tenant c717f263785d4679b16a122516247deb --action
access_as_shared
Created a new rbac_policy:
+---------------+--------------------------------------+
| Field
| Value
|
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Red Hat OpenStack Platform 8 Networking Guide
+---------------+--------------------------------------+
| action
| access_as_shared
|
| id
| 425cdd5c-c080-4045-a896-31d446551de7 |
| object_id
| 6e437ff0-d20f-4483-b627-c3749399bdca |
| object_type
| network
|
| target_tenant | c717f263785d4679b16a122516247deb
|
| tenant_id
| 4be7697a4258449a9677adb0fbb71e21
|
+---------------+--------------------------------------+
As a result, users in the Engineering tenant are able to connect instances to the web-servers
network.
12.2. Review your configured RBAC policies
1. Use the rbac-list option to retrieve the ID of your existing RBAC policies:
# neutron rbac-list
+--------------------------------------+-------------------------------------+
| id
| object_id
|
+--------------------------------------+-------------------------------------+
| 425cdd5c-c080-4045-a896-31d446551de7 | 6e437ff0-d20f-4483-b627c3749399bdca |
+--------------------------------------+-------------------------------------+
2. Use rbac-show to view the details of the specific RBAC entry:
# neutron rbac-show 425cdd5c-c080-4045-a896-31d446551de7
+---------------+--------------------------------------+
| Field
| Value
|
+---------------+--------------------------------------+
| action
| access_as_shared
|
| id
| 425cdd5c-c080-4045-a896-31d446551de7 |
| object_id
| 6e437ff0-d20f-4483-b627-c3749399bdca |
| object_type
| network
|
| target_tenant | c717f263785d4679b16a122516247deb
|
| tenant_id
| 4be7697a4258449a9677adb0fbb71e21
|
+---------------+--------------------------------------+
12.3. Delete a RBAC policy
1. Use the rbac-list option to retrieve the ID of your existing RBACs:
# neutron rbac-list
+--------------------------------------+-------------------------------------+
| id
| object_id
|
+--------------------------------------+-------------------------------------+
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CHAPTER 12. CONFIGURE RBAC
| 425cdd5c-c080-4045-a896-31d446551de7 | 6e437ff0-d20f-4483-b627c3749399bdca |
+--------------------------------------+-------------------------------------+
2. Use rbac-delete to delete the RBAC, based on it’s ID value:
# neutron rbac-delete 425cdd5c-c080-4045-a896-31d446551de7
Deleted rbac_policy: 425cdd5c-c080-4045-a896-31d446551de7
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CHAPTER 13. CONFIGURE DISTRIBUTED VIRTUAL
ROUTING (DVR)
Distributed Virtual Routing (DVR) allows you to place L3 Routers directly on Compute nodes. As a
result, instance traffic is directed between the Compute nodes (East-West) without first requiring
routing through a Network node. In addition, the Floating IP namespace is replicated between all
participating Compute nodes, meaning that instances with assigned floating IPs can send traffic
externally (North-South) without routing through the network node. Instances without floating IP
addresses still route SNAT traffic through the Networking node.
Red Hat OpenStack Platform 7 (kilo) added support for interconnecting between VLAN and
VXLAN/GRE when using distributed routers. This integration allows connectivity between VLANs
and VXLAN/GRE tunnels in DVR.
Note
DVR is included as a technology preview in Red Hat OpenStack Platform 8. For more
information on the support scope for features marked as technology previews, refer to
https://access.redhat.com/support/offerings/techpreview/
In the diagram below, the instances on separate subnets are able to communicate, without routing
through the Network node first:
13.1. Configure DVR
1. On the Network node, enable router_distributed in the neutron.conf file. This setting
ensures that all routers created in future are distributed by default.
router_distributed = True
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You can override the default behavior by editing the policy.json file:
neutron router-create --distributed=True/False
2. Configure the Layer 3 agent
On the Compute nodes, enable DVR in the l3_agent.ini file:
agent_mode = dvr
On the Network node, configure dvr_snat on the distributed router:
agent_mode = dvr_snat
3. Configure the Layer 2 agent
On the Network node and Compute nodes, enable DVR and L2 population on the L2 Agent. For
example, if using Open vSwitch, edit the ovs_neutron_plugin.ini file:
enable_distributed_routing = True
l2_population = True
4. Enable the L2 population mechanism driver in ML2
On the Controller, edit ml2_conf.ini:
[ml2]
mechanism_drivers = openvswitch, l2population #Other values may be
listed here as well
On the Compute nodes, edit ml2_conf.ini:
[agent]
l2_population = True
5. Restart the services for the changes to take effect:
On the Controller, restart the following services:
# systemctl restart neutron-server.service
# systemctl restart neutron-l3-agent.service
# systemctl restart neutron-openvswitch-agent.service
On the Compute node, restart the following services:
# systemctl restart neutron-l3-agent.service
# systemctl restart neutron-metadata-agent
Note
It is not currently possible to convert an existing non-distributed router to DVR. The router
should instead be deleted and re-created as DVR.
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CHAPTER 14. CONFIGURE LOAD BALANCING-AS-ASERVICE (LBAAS)
Load Balancing-as-a-Service (LBaaS) enables OpenStack Networking to distribute incoming
requests evenly between designated instances. This step-by-step guide configures OpenStack
Networking to use LBaaS with either the Open vSwitch (OVS) or the Linux Bridge plug-in.
Introduced in Red Hat OpenStack Platform 5, Load Balancing-as-a-Service (LBaaS) enables
OpenStack Networking to distribute incoming requests evenly between designated instances. This
ensures the workload is shared predictably among instances, and allows more effective use of
system resources. Incoming requests are distributed using one of these load balancing methods:
Round robin - Rotates requests evenly between multiple instances.
Source IP - Requests from a unique source IP address are consistently directed to the same
instance.
Least connections - Allocates requests to the instance with the least number of active
connections.
Table 1: LBaaS features
Table 14.1. LBaaS features
94
Feature
Description
Monitors
LBaaS provides availability monitoring with the
ping, TCP, HTTP and HTTPS GET methods.
Monitors are implemented to determine whether
pool members are available to handle requests.
Management
LBaaS is managed using a variety of tool sets. The
REST API is available for programmatic
administration and scripting. Users perform
administrative management of load balancers
through either the CLI (neutron) or the OpenStack
dashboard.
Connection limits
Ingress traffic can be shaped with connection
limits. This feature allows workload control and can
also assist with mitigating DoS (Denial of Service)
attacks.
Session persistence
LBaaS supports session persistence by ensuring
incoming requests are routed to the same instance
within a pool of multiple instances. LBaaS supports
routing decisions based on cookies and source IP
address.
CHAPTER 14. CONFIGURE LOAD BALANCING-AS-A-SERVICE (LBAAS)
Note
LBaaS is currently supported only with IPv4 addressing.
14.1. OpenStack Networking and LBaaS Topology
OpenStack Networking (neutron) services can be broadly classified into two categories.
1. - Neutron API server - This service runs the OpenStack Networking API server, which has the
main responsibility of providing an API for end users and services to interact with OpenStack
Networking. This server also has the responsibility of interacting with the underlying database to
store and retrieve tenant network, router, and loadbalancer details, among others.
2. - Neutron Agents - These are the services that deliver various network functionality for
OpenStack Networking.
neutron-dhcp-agent - manages DHCP IP addressing for tenant private networks.
neutron-l3-agent - facilitates layer 3 routing between tenant private networks, the external
network, and others.
neutron-lbaas-agent - provisions the LBaaS routers created by tenants.
14.1.1. Service Placement
The OpenStack Networking services can either run together on the same physical server, or on
separate dedicated servers.
The server that runs API server is usually called the Controller node, whereas the server that runs
the OpenStack Networking agents is called the Network node. An ideal production environment
would separate these components to their own dedicated nodes for performance and scalability
reasons, but a testing or PoC deployment might have them all running on the same node. This
chapter covers both of these scenarios; the section under Controller node configuration need to be
performed on the API server, whereas the section on Network node is performed on the server that
runs the LBaaS agent.
Note
If both the Controller and Network roles are on the same physical node, then the steps
must be performed on that server.
14.2. Configure LBaaS
This procedure configures OpenStack Networking to use LBaaS with either the Open vSwitch
(OVS) or the Linux Bridge plug-in. The Open vSwitch LBaaS driver is required when enabling
LBaaS for OVS-based plug-ins, including BigSwitch, Floodlight, NEC, NSX, and Ryu.
Note
By default, Red Hat OpenStack Plaftform includes support for the HAProxy driver for
LBaaS. You can review other supported service provider drivers at
https://access.redhat.com/certification.
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Perform these steps on nodes running the neutron-server service:
On the Controller node (API Server):
1. Enable the HAProxy plug-in using the service_provider parameter in the
/etc/neutron/neutron_lbaas.conf file:
service_provider =
LOADBALANCER:Haproxy:neutron.services.loadbalancer.drivers.haproxy.plug
in_driver.HaproxyOnHostPluginDriver:default
2. Enable the LBaaS plugin by setting the service_plugin value in the /etc/neutron/neutron.conf
file:
service_plugins = lbaas
3. Apply the new settings by restarting the _neutron-server services.
# systemctl restart neutron-server.service
14.2.1. Enable LBaaS Integration with Dashboard
Usually Horizon dashboard is run on the same node where neutron API service run. You can enable
Load Balancing in the Project section of the Dashboard user interface. Perform these steps on the
node running the Dashboard (horizon) service:
1. Change the enable_lb option to True in the /etc/openstack-dashboard/local_settings file:
OPENSTACK_NEUTRON_NETWORK = {'enable_lb': True,
2. Apply the new settings by restarting the httpd service.
# systemctl restart httpd.service
You can now view the Load Balancer management options in the Network list in dashboard’s
Project view.
14.3. On the network node (running the LBaaS Agent)
1. Enable the HAProxy load balancer in the /etc/neutron/lbaas_agent.ini file:
device_driver =
neutron.services.loadbalancer.drivers.haproxy.namespace_driver.HaproxyN
SDriver
2. Configure the user_group option in /etc/neutron/lbaas_agent.ini
# The user group
# user_group = nogroup
user_group = haproxy
3. Select the required driver in the /etc/neutron/lbaas_agent.ini file:
If using the Open vSwitch plug-in:
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CHAPTER 14. CONFIGURE LOAD BALANCING-AS-A-SERVICE (LBAAS)
interface_driver = neutron.agent.linux.interface.OVSInterfaceDriver
If using the Linux Bridge plug-in:
interface_driver = neutron.agent.linux.interface.BridgeInterfaceDriver
4. Apply the new settings by restarting the neutron-lbaas-agent service.
# systemctl restart neutron-lbaas-agent.service
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CHAPTER 15. TENANT NETWORKING WITH IPV6
This chapter describes how to implement IPv6 subnets in a tenant network. In addition to tenant
networking, as of director 7.3, IPv6-native deployments can be configured for the overcloud nodes.
Red Hat OpenStack Platform 6 added support for IPv6 in tenant networks. IPv6 subnets are created
within existing tenant networks, and support a number of address assignment modes: Stateless
Address Autoconfiguration (SLAAC), Stateful DHCPv6, and Stateless DHCPv6. This chapter
describes the IPv6 subnet creation options, and provides an example procedure that runs through
these steps.
15.1. IPv6 subnet options
IPv6 subnets are created using the neutron subnet-create command. In addition, you can
optionally specify the address mode and the Router Advertisement mode. The possible
combinations of these options are explained below:
98
RA Mode
Address Mode
Result
ipv6_ra_mode=not set
ipv6-address-mode=slaac
The instance receives an IPv6
address from the external router
(not managed by OpenStack
Networking) using SLAAC.
ipv6_ra_mode=not set
ipv6-address-mode=dhcpv6stateful
The instance receives an IPv6
address and optional information
from OpenStack Networking
(dnsmasq) using DHCPv6
stateful.
ipv6_ra_mode=not set
ipv6-address-mode=dhcpv6stateless
The instance receives an IPv6
address from the external router
using SLAAC, and optional
information from OpenStack
Networking (dnsmasq) using
DHCPv6 stateless.
ipv6_ra_mode=slaac
ipv6-address-mode=not-set
The instance uses SLAAC to
receive an IPv6 address from
OpenStack Networking (radvd).
ipv6_ra_mode=dhcpv6-stateful
ipv6-address-mode=not-set
The instance receives an IPv6
address and optional information
from an external DHCPv6 server
using DHCPv6 stateful.
CHAPTER 15. TENANT NETWORKING WITH IPV6
RA Mode
Address Mode
Result
ipv6_ra_mode=dhcpv6-stateless
ipv6-address-mode=not-set
The instance receives an IPv6
address from OpenStack
Networking (radvd) using
SLAAC, and optional information
from an external DHCPv6 server
using DHCPv6 stateless.
ipv6_ra_mode=slaac
ipv6-address-mode=slaac
The instance receives an IPv6
address from OpenStack
Networking (radvd) using
SLAAC.
ipv6_ra_mode=dhcpv6-stateful
ipv6-address-mode=dhcpv6stateful
The instance receives an IPv6
address from OpenStack
Networking (dnsmasq) using
DHCPv6 stateful, and optional
information from OpenStack
Networking (dnsmasq) using
DHCPv6 stateful.
ipv6_ra_mode=dhcpv6-stateless
ipv6-address-mode=dhcpv6stateless
The instance receives an IPv6
address from OpenStack
Networking (radvd) using
SLAAC, and optional information
from OpenStack Networking
(dnsmasq) using DHCPv6
stateless.
15.1.1. Create an IPv6 subnet using Stateful DHCPv6
This procedure makes use of the settings explained above to create an IPv6 subnet in a tenant
network. The initial steps gather the necessary tenant and network information, then use this to
construct a subnet creation command.
Note
OpenStack Networking only supports EUI-64 IPv6 address assignment for SLAAC. This
allows for simplified IPv6 networking, as hosts will self-assign addresses based on the
base 64-bits plus MAC address. Attempts to create subnets with a different netmask and
address_assign_type of SLAAC will fail.
1. Retrieve the tenant id of the Project where you want to create the IPv6 subnet. These values are
unique between OpenStack deployments, so your value will differ from the one supplied. In this
example, the QA tenant will receive the IPv6 subnet.
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# keystone tenant-list
+----------------------------------+----------+---------+
|
id
|
name
| enabled |
+----------------------------------+----------+---------+
| 25837c567ed5458fbb441d39862e1399 |
QA
|
True |
| f59f631a77264a8eb0defc898cb836af | admin
|
True |
| 4e2e1951e70643b5af7ed52f3ff36539 |
demo
|
True |
| 8561dff8310e4cd8be4b6fd03dc8acf5 | services |
True |
+----------------------------------+----------+---------+
2. Retrieve a list of all networks present in OpenStack Networking (neutron), and note the name of
the network that will host the IPv6 subnet. In this example, database-servers will be used.
# neutron net-list
+--------------------------------------+------------------+------------------------------------------------------------+
| id
| name
| subnets
|
+--------------------------------------+------------------+------------------------------------------------------------+
| 8357062a-0dc2-4146-8a7f-d2575165e363 | private
| c17f74c4db41-4538-af40-48670069af70 10.0.0.0/24
|
| 31d61f7d-287e-4ada-ac29-ed7017a54542 | public
| 303ced036019-4e79-a21c-1942a460b920 172.24.4.224/28
|
| 6aff6826-4278-4a35-b74d-b0ca0cbba340 | database-servers |
|
+--------------------------------------+------------------+------------------------------------------------------------+
3. Use the QA tenant-id (25837c567ed5458fbb441d39862e1399) from the above steps to
construct the network creation command. Another requirement is the name of the destination
network that will host the IPv6 subnet. In this example, the database-servers network is used:
# neutron subnet-create --ip-version 6 --ipv6_address_mode=dhcpv6stateful --tenant-id 25837c567ed5458fbb441d39862e1399 database-servers
fdf8:f53b:82e4::53/125
Created a new subnet:
+-------------------+-------------------------------------------------------------+
| Field
| Value
|
+-------------------+-------------------------------------------------------------+
| allocation_pools | {"start": "fdf8:f53b:82e4::52", "end":
"fdf8:f53b:82e4::56"} |
| cidr
| fdf8:f53b:82e4::53/125
|
| dns_nameservers
|
|
| enable_dhcp
| True
|
| gateway_ip
| fdf8:f53b:82e4::51
|
| host_routes
|
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CHAPTER 15. TENANT NETWORKING WITH IPV6
|
| id
| cdfc3398-997b-46eb-9db1-ebbd88f7de05
|
| ip_version
| 6
|
| ipv6_address_mode | dhcpv6-stateful
|
| ipv6_ra_mode
|
|
| name
|
|
| network_id
| 6aff6826-4278-4a35-b74d-b0ca0cbba340
|
| tenant_id
| 25837c567ed5458fbb441d39862e1399
|
+-------------------+-------------------------------------------------------------+
4. Validate this configuration by reviewing the network list. Note that the entry for database-servers
now reflects the newly created IPv6 subnet:
# neutron net-list
+--------------------------------------+------------------+------------------------------------------------------------+
| id
| name
| subnets
|
+--------------------------------------+------------------+------------------------------------------------------------+
| 6aff6826-4278-4a35-b74d-b0ca0cbba340 | database-servers | cdfc3398997b-46eb-9db1-ebbd88f7de05 fdf8:f53b:82e4::50/125 |
| 8357062a-0dc2-4146-8a7f-d2575165e363 | private
| c17f74c4db41-4538-af40-48670069af70 10.0.0.0/24
|
| 31d61f7d-287e-4ada-ac29-ed7017a54542 | public
| 303ced036019-4e79-a21c-1942a460b920 172.24.4.224/28
|
+--------------------------------------+------------------+------------------------------------------------------------+
As a result of this configuration, instances created by the QA tenant are able to receive a DHCP
IPv6 address when added to the database-servers subnet:
# nova list
+--------------------------------------+------------+--------+-----------+-------------+-------------------------------------+
| ID
| Name
| Status | Task
State | Power State | Networks
|
+--------------------------------------+------------+--------+-----------+-------------+-------------------------------------+
| fad04b7a-75b5-4f96-aed9-b40654b56e03 | corp-vm-01 | ACTIVE | | Running
| database-servers=fdf8:f53b:82e4::52 |
+--------------------------------------+------------+--------+-----------+-------------+-------------------------------------+
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CHAPTER 16. MANAGE TENANT QUOTAS
This chapter explains the management of Tenant/Project quotas for OpenStack Networking
components.
OpenStack Networking (neutron) supports the use of quotas to constrain the number of resources
created by tenants/projects. For example, you can limit the number of routers a tenant can create
by changing the quota_router value in the neutron.conf file:
quota_router = 10
This configuration limits each tenant to a maximum of 10 routers.
Further quota settings are available for the various network components:
16.1. L3 quota options
Quota options available for L3 networking: quota_floatingip - Number of floating IPs allowed per
tenant. quota_network - Number of networks allowed per tenant. quota_port - Number of ports
allowed per tenant. quota_router - Number of routers allowed per tenant. quota_subnet - Number
of subnets allowed per tenant. quota_vip - Number of vips allowed per tenant.
16.2. Firewall quota options
Quota options governing firewall management: quota_firewall - Number of firewalls allowed per
tenant. quota_firewall_policy - Number of firewall policies allowed per tenant. quota_firewall_rule
- Number of firewall rules allowed per tenant.
16.3. Security group quota options
Quota options for managing the permitted number of security groups: quota_security_group Number of security groups allowed per tenant. quota_security_group_rule - Number of security
group rules allowed per tenant.
16.4. Management quota options
Quota options for administrators to consider: default_quota - Default number of resource allowed
per tenant. quota_health_monitor - Number of health monitors allowed per tenant. Health monitors
do not consume resources, however the quota option is available due to the OpenStack Networking
back end handling members as resource consumers. quota_member - Number of pool members
allowed per tenant. Members do not consume resources, however the quota option is available due
to the OpenStack Networking back end handling members as resource consumers. quota_pool Number of pools allowed per tenant.
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CHAPTER 17. CONFIGURE FIREWALL-AS-A-SERVICE (FWAAS)
CHAPTER 17. CONFIGURE FIREWALL-AS-A-SERVICE
(FWAAS)
The Firewall-as-a-Service (FWaaS) plug-in adds perimeter firewall management to OpenStack
Networking (neutron). FWaaS uses iptables to apply firewall policy to all virtual routers within a
project, and supports one firewall policy and logical firewall instance per project.
FWaaS operates at the perimeter by filtering traffic at the OpenStack Networking (neutron) router.
This distinguishes it from security groups, which operate at the instance level.
Note
FWaaS is currently in technical preview; untested operation is not recommended.
The example diagram below illustrates the flow of ingress and egress traffic for the VM2 instance:
Figure 1. FWaaS architecture
17.1. Enable FWaaS
1. Install the FWaaS packages:
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# yum install openstack-neutron-fwaas python-neutron-fwaas
2. Enable the FWaaS plugin in the neutron.conf file:
service_plugins = neutron.services.firewall.fwaas_plugin.FirewallPlugin
3. Configure FWaaS in the fwaas_driver.ini file:
[fwaas]
driver =
neutron.services.firewall.drivers.linux.iptables_fwaas.IptablesFwaasDri
ver
enabled = True
[service_providers]
service_provider=LOADBALANCER:Haproxy:neutron.services.loadbalancer.dri
vers.haproxy.plugin_driver.HaproxyOnHostPluginDriver:default
4. FWaaS management options are available in OpenStack dashboard. Enable this option in the
local_settings.py file, usually located on the Controller node:
/usr/share/openstackdashboard/openstack_dashboard/local/local_settings.py
'enable_firewall' = True
5. Restart neutron-server to apply the changes.
# systemctl restart neutron-server
17.2. Configure FWaaS
First create the firewall rules and create a policy to contain them, then create a firewall and apply the
policy:
1. Create a firewall rule:
$ neutron firewall-rule-create --protocol -destination-port --action
The CLI requires a protocol value; if the rule is protocol agnostic, the any value can be used.
2. Create a firewall policy:
$ neutron firewall-policy-create --firewall-rules "" myfirewallpolicy
The order of the rules specified above is important. You can create an empty firewall policy and add
rules later, either with the update operation (when adding multiple rules) or with the insert-rule
operations (when adding a single rule).
Note: FWaaS always adds a default deny all rule at the lowest precedence of each policy.
Consequently, a firewall policy with no rules blocks all traffic by default.
17.3. Create a firewall
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17.3. Create a firewall
$ neutron firewall-create
The firewall remains in PENDING_CREATE state until an OpenStack Networking router is created,
and an interface is attached.
17.4. Allowed-address-pairs
Allowed-address-pairs allow you to specify mac_address/ip_address (CIDR) pairs that pass through
a port regardless of subnet. This enables the use of protocols such as VRRP, which floats an IP
address between two instances to enable fast data plane failover.
Note
The allowed-address-pairs extension is currently only supported by these plug-ins: ML2,
Open vSwitch, and VMware NSX.
17.4.1. Basic allowed-address-pairs operations
Create a port with a specific allowed-address-pairs:
# neutron port-create net1 --allowed-address-pairs type=dict list=true
mac_address=,ip_address=
17.4.2. Adding allowed-address-pairs
# neutron port-update --allowed-address-pairs type=dict
list=true mac_address=,ip_address=
Note
OpenStack Networking prevents setting an allowed-address-pair that matches the
mac_address and ip_address of a port. This is because such a setting would have no
effect since traffic matching the mac_address and ip_address is already allowed to pass
through the port.
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CHAPTER 18. CONFIGURE LAYER 3 HIGH AVAILABILITY
This chapter explains the role of Layer 3 High Availability in an OpenStack Networking deployment
and includes implementation steps for protecting your network’s virtual routers.
18.1. OpenStack Networking without HA
An OpenStack Networking deployment without any high availability features is going to be
vulnerable to physical node failures.
In a typical deployment, tenants create virtual routers, which are scheduled to run on physical L3
agent nodes. This becomes an issue when you lose a L3 agent node and the dependent virtual
machines subsequently lose connectivity to external networks. Any floating IP addresses will also be
unavailable.
18.2. Overview of Layer 3 High Availability
This active/passive high availability configuration uses the industry standard VRRP (as defined in
RFC 3768) to protect tenant routers and floating IP addresses. A virtual router is randomly
scheduled across multiple OpenStack Networking nodes, with one designated as the active, and the
remainder serving in a standby role.
Note
A successful deployment of Layer 3 High Availability requires that the redundant
OpenStack Networking nodes maintain similar configurations, including floating IP ranges
and access to external networks.
In the diagram below, the active Router1 and Router2 are running on separate physical L3 agent
nodes. Layer 3 High Availability has scheduled backup virtual routers on the corresponding nodes,
ready to resume service in the case of a physical node failure:
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CHAPTER 18. CONFIGURE LAYER 3 HIGH AVAILABILITY
When the L3 agent node fails, Layer 3 High Availability reschedules the affected virtual router and
floating IP addresses to a working node:
During a failover event, instance TCP sessions through floating IPs remain unaffected, and will
migrate to the new L3 node without disruption. Only SNAT traffic is affected by failover events.
The L3 agent itself is further protected when in an active/active HA mode.
18.2.1. Failover conditions
Layer 3 High Availability will automatically reschedule protected resources in the following events:
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Red Hat OpenStack Platform 8 Networking Guide
The L3 agent node shuts down or otherwise loses power due to hardware failure.
L3 agent node becomes isolated from the physical network and loses connectivity.
Note
Manually stopping the L3 agent service does not induce a failover event.
18.3. Tenant considerations
Layer 3 High Availability configuration occurs in the back end and is invisible to the tenant. They can
continue to create and manage their virtual routers as usual, however there are some limitations to
be aware of when designing your Layer 3 High Availability implementation:
Layer 3 High Availability supports up to 255 virtual routers per tenant.
Internal VRRP messages are transported within a separate internal network, created
automatically for each project. This process occurs transparently to the user.
18.4. Background changes
The Neutron API has been updated to allow administrators to set the --ha=True/False flag when
creating a router, which overrides the (Default) configuration of l3_ha in neutron.conf. See the next
section for the necessary configuration steps.
18.4.1. Changes to neutron-server
Layer 3 High Availability assigns the active role randomly, regardless of the scheduler used by
OpenStack Networking (whether random or leastrouter).
The database schema has been modified to handle allocation of VIPs to virtual routers.
A transport network is created to direct Layer 3 High Availability traffic as described above.
18.4.2. Changes to L3 agent
A new keepalived manager has been added, providing load-balancing and HA capabilities.
IP addresses are converted to VIPs.
18.5. Configuration Steps
This procedure enables Layer 3 High Availability on the OpenStack Networking and L3 agent
nodes.
18.6. Configure the OpenStack Networking node
1. Configure Layer 3 High Availability in the neutron.conf file by enabling L3 HA and defining the
number of L3 agent nodes that should protect each virtual router:
l3_ha = True
max_l3_agents_per_router = 2
min_l3_agents_per_router = 2
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These settings are explained below:
l3_ha - When set to True, all virtual routers created from this point onwards will default to HA
(and not legacy) routers. Administrators can override the value for each router using:
# neutron router-create --ha= routerName
max_l3_agents_per_router - Set this to a value between the minimum and total number of
network nodes in your deployment. For example, if you deploy four OpenStack Networking
nodes but set max to 2, only two L3 agents will protect each HA virtual router: One active, and
one standby. In addition, each time a new L3 agent node is deployed, additional standby
versions of the virtual routers are scheduled until the max_l3_agents_per_router limit is reached.
As a result, you can scale out the number of standby routers by adding new L3 agents.
min_l3_agents_per_router - The min setting ensures that the HA rules remain enforced. This
setting is validated during the virtual router creation process to ensure a sufficient number of L3
Agent nodes are available to provide HA. For example, if you have two network nodes and one
becomes unavailable, no new routers can be created during that time, as you need at least min
active L3 agents when creating a HA router.
2. Restart the neutron-server service for the change to take effect:
# systemctl restart neutron-server.service
18.7. Review your configuration
Running the ip address command within the virtual router namespace will now return a HA device in
the result, prefixed with ha-.
# ip netns exec qrouter-b30064f9-414e-4c98-ab42-646197c74020 ip address
2794: ha-45249562-ec: mtu 1500 qdisc
noqueue state DOWN group default
link/ether 12:34:56:78:2b:5d brd ff:ff:ff:ff:ff:ff
inet 169.254.0.2/24 brd 169.254.0.255 scope global ha-54b92d86-4f
With Layer 3 High Availability now enabled, virtual routers and floating IP addresses are protected
against individual node failure.
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CHAPTER 19. SR-IOV SUPPORT FOR VIRTUAL
NETWORKING
RHEL OpenStack Platform 6 extended single root I/O virtualization (SR-IOV) support to virtual
machine networking. This means that OpenStack is able to put aside the previous requirement for
virtual bridges, and instead extend the physical NIC’s capabilities directly through to the instance. In
addition, support for IEEE 802.1br allows virtual NICs to integrate with, and be managed by, the
physical switch.
19.1. Configure SR-IOV in your RHEL OpenStack Platform deployment
This chapter contains procedures for configuring SR-IOV to pass a physical NIC through to a virtual
instance. These steps assume a deployment using a Controller node, an OpenStack Networking
(neutron) node, and multiple Compute (nova) nodes.
Note: Virtual machine instances using SR-IOV ports and virtual machine instances using regular
ports (e.g. linked to Open vSwitch bridge), can communicate with each other across the network
assuming that the appropriate L2 configuration (i.e. flat, VLAN) is in place. At present, there is a
limitation where instances using SR-IOV ports and instances using regular vSwitch ports which
reside on the same Compute node cannot communicate with each other if they are sharing the
same Physical Function (PF) on the network adapter.
19.2. Create Virtual Functions on the Compute node
Perform these steps on all Compute nodes with supported hardware.
Note: Please refer to this article for details on supported drivers.
This procedure configures a system to passthrough an Intel 82576 network device. Virtual
Functions are also created, which can then be used by instances for SR-IOV access to the device.
1. Ensure that Intel VT-d or AMD IOMMU are enabled in the system’s BIOS. Refer to the machine’s
BIOS configuration menu, or other means available from the manufacturer.
2. Ensure that Intel VT-d or AMD IOMMU are enabled in the operating system:
For Intel VT-d systems, refer to the procedure here.
For AMD IOMMU systems, refer to the procedure here.
3. Run the lspci command to ensure the network device is recognized by the system:
[root@compute ~]# lspci | grep 82576
The network device is included in the results:
03:00.0 Ethernet controller: Intel Corporation 82576 Gigabit Network
Connection (rev 01)
03:00.1 Ethernet controller: Intel Corporation 82576 Gigabit Network
Connection (rev 01)
4. Perform these steps to activate Virtual Functions on the Compute node: 4a. Remove the kernel
module. This will allow it to be configured in the next step:
[root@compute ~]# modprobe -r igb
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CHAPTER 19. SR-IOV SUPPORT FOR VIRTUAL NETWORKING
Note: The module used by the SRIOV-supported NIC should be used in step 4 , rather than igb for
other NICs (for example, ixgbe or mlx4_core). Confirm the driver by running the ethtool
command. In this example, em1 is the PF (Physical Function) we want to use:
[root@compute ~]# ethtool -i em1 | grep ^driver
4b. Start the module with max_vfs set to 7 (or up to the maximum supported).
[root@compute ~]# modprobe igb max_vfs=7
4c. Make the Virtual Functions persistent:
[root@compute ~]# echo "options igb max_vfs=7"
>>/etc/modprobe.d/igb.conf
Note: For Red Hat Enterprise Linux 7, to make the aforementioned changes persistent, rebuild the
initial ramdisk image after completing step 4.
Note: Regarding the persistence of the settings in steps 4c. and 4d.: The modprobe command
enables Virtual Functions on all NICs that use the same kernel module, and makes the change
persist through system reboots. It is possible to enable VFs for only a specific NIC, however there
are some possible issues that can result. For example, this command enables VFs for the
enp4s0f1 interface:
# echo 7 > /sys/class/net/enp4s0f1/device/sriov_numvfs
However, this setting will not persist after a reboot. A possible workaround is to add this to rc.local,
but this has its own limitation, as described in the note below:
# chmod +x /etc/rc.d/rc.local
# echo "echo 7 > /sys/class/net/enp4s0f1/device/sriov_numvfs" >>
/etc/rc.local
Note: Since the addition of systemd, Red Hat Enterprise Linux starts services in parallel, rather than
in series. This means that rc.local no longer executes at a predictable point in the boot process. As
a result, unexpected behavior can occur, and this configuration is not recommended.
4d. Activate Intel VT-d in the kernel by appending the intel_iommu=pt and igb.max_vfs=7
parameters to the kernel command line. You can either change your current settings if you are
going to always boot the kernel this way, or you can create a custom menu entry with these
parameters, in which case your system will boot with these parameters by default, but you will also
be able to boot the kernel without these parameters if need be.
• To change your current kernel command line parameters, run the following command:
[root@compute ~]# grubby --update-kernel=ALL --args="intel_iommu=pt
igb.max_vfs=7"
For more information on using grubby, see Configuring GRUB 2 Using the grubby Tool in the
System Administrator’s Guide.
Note: If using a Dell Power Edge R630 node, you will need to use intel_iommu=on instead of
intel_iommu=pt. You can enable this using grubby:
# grubby --update-kernel=ALL --args="intel_iommu=on"
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• To create a custom menu entry:
i. Find the default entry in grub:
[root@compute ~]# grub2-editenv list
saved_entry=Red Hat Enterprise Linux Server (3.10.0-123.9.2.el7.x86_64)
7.0 (Maipo)
ii. a. Copy the desired menuentry starting with the value of saved_entry from /boot/grub2/grub.cfg to
/etc/grub.d/40_custom. The entry begins with the line starting with "menuentry" and ends with a line
containing "}" b. Change the title after menuentry c. Add intel_iommu=pt igb.max_vfs=7 to the end
of the line starting with linux16.
For example:
menuentry 'Red Hat Enterprise Linux Server, with Linux 3.10.0123.el7.x86_64 - SRIOV' --class red --class gnu-linux --class gnu -class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0123.el7.x86_64-advanced-4718717c-73ad-4f5f-800f-f415adfccd01' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_msdos
insmod ext2
set root='hd0,msdos2'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos2 -hint-efi=hd0,msdos2 --hint-baremetal=ahci0,msdos2 --hint='hd0,msdos2'
5edd1db4-1ebc-465c-8212-552a9c97456e
else
search --no-floppy --fs-uuid --set=root 5edd1db4-1ebc-465c-8212552a9c97456e
fi
linux16 /vmlinuz-3.10.0-123.el7.x86_64 root=UUID=4718717c-73ad4f5f-800f-f415adfccd01 ro vconsole.font=latarcyrheb-sun16 biosdevname=0
crashkernel=auto vconsole.keymap=us nofb console=ttyS0,115200
LANG=en_US.UTF-8 intel_iommu=pt igb.max_vfs=7
initrd16 /initramfs-3.10.0-123.el7.x86_64.img
}
iii. Update grub.cfg to apply the change config file:
[root@compute ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
iv. Change the default entry:
[root@compute ~]# grub2-set-default 'Red Hat Enterprise Linux Server,
with Linux 3.10.0-123.el7.x86_64 - SRIOV'
v. Create the dist.conf configuration file.
Note: Before performing this step, review the section describing the effects of
allow_unsafe_interrupts: Review the allow_unsafe_interrupts setting.
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CHAPTER 19. SR-IOV SUPPORT FOR VIRTUAL NETWORKING
[root@compute ~]# echo "options vfio_iommu_type1
allow_unsafe_interrupts=1" > /etc/modprobe.d/dist.conf
5. Reboot the server to apply the new kernel parameters:
[root@compute ~]# systemctl reboot
6. Review the SR-IOV kernel module on the Compute node. Confirm that the module has been
loaded by running lsmod:
[root@compute ~]#
lsmod |grep igb
The filtered results will include the necessary module:
igb
dca
87592
6708
0
1 igb
7. Review the PCI vendor ID Make a note of the PCI vendor ID (in vendor_id:product_id format) of
your network adapter. Extract this from the output of the lspci command using the -nn flag. For
example:
[root@compute ~]# lspci -nn | grep
05:00.0 Ethernet controller [0200]:
Network Connection [8086:10c9] (rev
05:00.1 Ethernet controller [0200]:
Network Connection [8086:10c9] (rev
05:10.0 Ethernet controller [0200]:
Function [8086:10ca] (rev 01)
-i 82576
Intel Corporation 82576 Gigabit
01)
Intel Corporation 82576 Gigabit
01)
Intel Corporation 82576 Virtual
Note: This parameter may differ depending on your network adapter hardware.
8. Review the new Virtual Functions Use lspci to list the newly-created VFs:
[root@compute ~]# lspci | grep 82576
The results will now include the device plus the Virtual Functions:
0b:00.0 Ethernet controller:
Connection (rev 01)
0b:00.1 Ethernet controller:
Connection(rev 01)
0b:10.0 Ethernet controller:
(rev 01)
0b:10.1 Ethernet controller:
(rev 01)
0b:10.2 Ethernet controller:
(rev 01)
0b:10.3 Ethernet controller:
(rev 01)
0b:10.4 Ethernet controller:
(rev 01)
0b:10.5 Ethernet controller:
(rev 01)
0b:10.6 Ethernet controller:
Intel Corporation 82576 Gigabit Network
Intel Corporation 82576 Gigabit Network
Intel Corporation 82576 Virtual Function
Intel Corporation 82576 Virtual Function
Intel Corporation 82576 Virtual Function
Intel Corporation 82576 Virtual Function
Intel Corporation 82576 Virtual Function
Intel Corporation 82576 Virtual Function
Intel Corporation 82576 Virtual Function
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(rev 01)
0b:10.7 Ethernet
(rev 01)
0b:11.0 Ethernet
(rev 01)
0b:11.1 Ethernet
(rev 01)
0b:11.2 Ethernet
(rev 01)
0b:11.3 Ethernet
(rev 01)
0b:11.4 Ethernet
(rev 01)
0b:11.5 Ethernet
(rev 01)
controller: Intel Corporation 82576 Virtual Function
controller: Intel Corporation 82576 Virtual Function
controller: Intel Corporation 82576 Virtual Function
controller: Intel Corporation 82576 Virtual Function
controller: Intel Corporation 82576 Virtual Function
controller: Intel Corporation 82576 Virtual Function
controller: Intel Corporation 82576 Virtual Function
19.3. Configure SR-IOV on the Network Node
OpenStack Networking (neutron) uses a ML2 mechanism driver to support SR-IOV. Perform these
steps on the Network node to configure the SR-IOV driver.
1. Enable sriovnicswitch in the /etc/neutron/plugin.ini file. For example, this configuration enables
the SR-IOV mechanism driver alongside Open vSwitch.
Note: sriovnicswitch does not support the current interface drivers for DHCP Agent, so openvswitch
(or other mechanism driver with VLAN support) is a requirement when using sriovnicswitch.
[ml2]
tenant_network_types = vlan
type_drivers = vlan
mechanism_drivers = openvswitch, sriovnicswitch
[ml2_type_vlan]
network_vlan_ranges = physnet1:15:20
network_vlan_ranges - In this example, physnet1 is used as the network label, followed by the
specified VLAN range of 15-20.
Note: The mechanism driver sriovnicswitch currently supports only the flat and vlan drivers.
2. Optional - If you require VF link state and admin state management, and your vendor supports
these features, then enable this option in the /etc/neutron/plugins/ml2/ml2_conf_sriov.ini file:
[root@network ~]# openstack-config --set
/etc/neutron/plugins/ml2/ml2_conf_sriov.ini ml2_sriov agent_required
True
3. Optional - The supported vendor_id/product_id couples are 15b3:1004, 8086:10ca. Specify your
NIC vendor’s product ID if it differs from these. For example:
[ml2_sriov]
supported_pci_vendor_devs = 15b3:1004,8086:10ca
4. Configure neutron-server.service to use the ml2_conf_sriov.ini file. For example:
[root@network ~]# vi /usr/lib/systemd/system/neutron-server.service
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CHAPTER 19. SR-IOV SUPPORT FOR VIRTUAL NETWORKING
[Service]
Type=notify
User=neutron
ExecStart=/usr/bin/neutron-server --config-file
/usr/share/neutron/neutron-dist.conf --config-file
/etc/neutron/neutron.conf --config-file /etc/neutron/plugin.ini -config-file /etc/neutron/plugins/ml2/ml2_conf_sriov.ini --log-file
/var/log/neutron/server.log
5. Restart the neutron-server service to apply the configuration:
[root@network ~]# systemctl restart neutron-server.service
19.4. Configure SR-IOV on the Controller Node
1. To allow proper scheduling of SR-IOV devices, the Compute scheduler needs to use
FilterScheduler with the PciPassthroughFilter filter. Apply this configuration in the nova.conf file on
the Controller node. For example:
scheduler_available_filters=nova.scheduler.filters.all_filters
scheduler_default_filters=RetryFilter,AvailabilityZoneFilter,RamFilter,
ComputeFilter,ComputeCapabilitiesFilter,ImagePropertiesFilter,CoreFilte
r, PciPassthroughFilter
2. Restart the Compute scheduler to apply the change:
[root@compute ~]# systemctl restart openstack-nova-scheduler.service
19.5. Configure SR-IOV in Compute
On all Compute nodes, associate the available VFs with each physical network: 1. Define the
entries in the the nova.conf file. This example adds the VF network matching enp5s0f1, and tags
physical_network as physnet1, the network label previously configured in network_vlan_ranges.
pci_passthrough_whitelist={"devname": "enp5s0f1",
"physical_network":"physnet1"}
This example adds the PF network matching vendor ID 8086, and tags physical_network as
physnet1: ~ pci_passthrough_whitelist = \{"vendor_id": "8086","product_id": "10ac",
"physical_network":"physnet1"} ~
PCI passthrough whitelist entries use the following syntax:
["device_id": "",] ["product_id": "",]
["address": "[[[[]:]]:][][.[]]" |
"devname": "Ethernet Interface Name",]
"physical_network":"Network label string"
id - The id setting accepts the * wildcard value, or a valid device/product id. You can use lspci to
list the valid device names.
address - The address value uses the same syntax as displayed by lspci using the -s switch.
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devname - The devname is a valid PCI device name. You can list the available names using
ifconfig -a. This entry must correspond to either a PF or VF value that is associated with a vNIC.
If the device defined by the address or devname corresponds to a SR-IOV PF, all the VFs under
the PF will match the entry. It is possible to associate 0 or more tags with an entry.
physical_network - When using SR-IOV networking, "physical_network" is used to define the
physical network that devices are attached to.
You can configure multiple whitelist entries per host. The fields device_id, product_id, and address
or devname will be matched against PCI devices that are returned as a result of querying libvirt.
2. Apply the changes by restarting the nova-compute service:
[root@compute ~]# systemctl restart openstack-nova-compute
19.6. Enable the OpenStack Networking SR-IOV agent
The optional OpenStack Networking SR-IOV agent enables management of the admin_state port.
This agent integrates with the network adapter, allowing administrators to toggle the up/down
administrative state of Virtual Functions.
In addition, if agent_required=True has been configured on the OpenStack Networking (neutron)
server, you must run the OpenStack Networking SR-IOV Agent on each Compute node.
Note: Not all NIC vendors currently support port status management using this agent.
1. Install the sriov-nic-agent package in order to complete the following steps:
[root@compute ~]# yum install openstack-neutron-sriov-nic-agent
2. Enable NoopFirewallDriver in the /etc/neutron/plugin.ini file:
[root@compute ~]# openstack-config --set /etc/neutron/plugin.ini
securitygroup firewall_driver neutron.agent.firewall.NoopFirewallDriver
3. Add mappings to the /etc/neutron/plugins/ml2/ml2_conf_sriov.ini file. In this example, physnet1 is
the physical network, and enp4s0f1 is the physical function. Leave exclude_devices blank to allow
the agent to manage all associated VFs.
[sriov_nic]
physical_device_mappings = physnet1:enp4s0f1
exclude_devices =
4. Optional - Exclude VFs To exclude specific VFs from agent configuration, list them in the
sriov_nic section. For example:
exclude_devices = eth1:0000:07:00.2; 0000:07:00.3, eth2:0000:05:00.1;
0000:05:00.2
5. Configure neutron-sriov-nic-agent.service to use the ml2_conf_sriov.ini file. For example:
[root@network ~]# vi /usr/lib/systemd/system/neutron-sriov-nicagent.service
[Service]
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CHAPTER 19. SR-IOV SUPPORT FOR VIRTUAL NETWORKING
Type=simple
User=neutron
ExecStart=/usr/bin/neutron-sriov-nic-agent --config-file
/usr/share/neutron/neutron-dist.conf --config-file
/etc/neutron/neutron.conf --log-file /var/log/neutron/sriov-nicagent.log --config-file /etc/neutron/plugins/ml2/ml2_conf_sriov.ini
6. Start the OpenStack Networking SR-IOV agent:
[root@network ~]# systemctl enable neutron-sriov-nic-agent.service
[root@network ~]# systemctl start neutron-sriov-nic-agent.service
19.7. Configure an instance to use the SR-IOV port
In this example, the SR-IOV port is added to the web network.
1. Retrieve the list of available networks
[root@network ~]# neutron net-list
+--------------------------------------+---------+-----------------------------------------------------+
| id
| name
| subnets
|
+--------------------------------------+---------+-----------------------------------------------------+
| 3c97eb09-957d-4ed7-b80e-6f052082b0f9 | corp
| 78328449-796b-49cc96a8-1daba7a910be 172.24.4.224/28 |
| 721d555e-c2e8-4988-a66f-f7cbe493afdb | web
| 140e936e-0081-4412a5ef-d05bacf3d1d7 10.0.0.0/24
|
+--------------------------------------+---------+-----------------------------------------------------+
The result lists the networks that have been created in OpenStack Networking, and includes subnet
details.
2. Create the port inside the web network
[root@network ~]# neutron port-create web --name sr-iov --binding:vnictype direct
Created a new port:
+-----------------------+--------------------------------------------------------------------------------+
| Field
| Value
|
+-----------------------+--------------------------------------------------------------------------------+
| admin_state_up
| True
|
| allowed_address_pairs |
|
| binding:host_id
|
|
| binding:profile
| {}
|
| binding:vif_details
| {}
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Red Hat OpenStack Platform 8 Networking Guide
|
| binding:vif_type
| unbound
|
| binding:vnic_type
| normal
|
| device_id
|
|
| device_owner
|
|
| fixed_ips
| {"subnet_id": "140e936e-0081-4412-a5efd05bacf3d1d7", "ip_address": "10.0.0.2"} |
| id
| a2122b4d-c9a9-4a40-9b67-ca514ea10a1b
|
| mac_address
| fa:16:3e:b1:53:b3
|
| name
| sr-iov
|
| network_id
| 721d555e-c2e8-4988-a66f-f7cbe493afdb
|
| security_groups
| 3f06b19d-ec28-427b-8ec7-db2699c63e3d
|
| status
| DOWN
|
| tenant_id
| 7981849293f24ed48ed19f3f30e69690
|
+-----------------------+--------------------------------------------------------------------------------+
3. Create an instance using the new port Create a new instance named webserver01, and configure
it to use the new port, using the port ID from the previous output in the id field:
Note: You can retrieve a list of available images and their UUIDs using the glance image-list
command.
[root@compute ~]# nova boot --flavor m1.tiny --image 59a66200-45d24b21-982b-d06bc26ff2d0 --nic port-id=a2122b4d-c9a9-4a40-9b67ca514ea10a1b webserver01
Your new instance webserver01 has been created and configured to use the SR-IOV port.
19.8. Review the allow_unsafe_interrupts setting
Platform support for interrupt remapping is required to fully isolate a guest with assigned devices
from the host. Without such support, the host may be vulnerable to interrupt injection attacks from a
malicious guest. In an environment where guests are trusted, the admin may opt-in to still allow PCI
device assignment using the allow_unsafe_interrupts option. Review whether you need to enable
allow_unsafe_interrupts on your host. If the IOMMU on the host supports interrupt remapping, then
there is no need to enable this feature.
1. Use dmesg to confirm whether your host supports IOMMU interrupt remapping:
[root@compute ~]# dmesg |grep ecap
If bit 3 of the ecap (0xf020ff → …1111) is 1 , this indicates that the IOMMU supports interrupt
remapping.
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CHAPTER 19. SR-IOV SUPPORT FOR VIRTUAL NETWORKING
2. Confirm whether IRQ remapping is enabled:
[root@compute ~]# dmesg |grep "Enabled IRQ"
[
0.033413] Enabled IRQ remapping in x2apic mode
Note: "IRQ remapping" can be disabled manually by adding intremap=off to grub.conf.
3. If the host’s IOMMU does not support interrupt remapping, you will need to enable
allow_unsafe_assigned_interrupts=1 in the kvm module.
19.9. Additional considerations
When selecting a vNIC type, note that vnic_type=macvtap is not currently supported.
VM migration with SR-IOV attached instances is not supported.
Security Groups can not currently be used with SR-IOV enabled ports.
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