UNIVERSAL BROADBAND ROUTER UBR10012 Troubgd

User Manual: UNIVERSAL BROADBAND ROUTER UBR10012

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Page Count: 86

Contents
Preface
Basic Troubleshooting Tasks and Startup Issues
PEM Faults and Fan Assembly Failures
Troubleshooting PRE-1 Modules
Troubleshooting Line Cards
Replacing or Recovering Passwords
- Password Recovery Procedure Overview
- Password Recovery Procedure
Unsupported Commands
Recommended Tools and Test Equipment
Index

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Cisco uBR10012 Universal Broadband

Router Troubleshooting Guide

October 2004

Text Part Number: OL-1237-01

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Cisco uBR10012 Universal Broadband Router Troubleshooting Guide

OL-1237-01

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iii

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CONTENTS

Preface vii

Purpose vii

Audience vii

Document Organization viii

Other Electrical Problems

If the electrical problem cannot be traced to a PEM, check the unit for:

•Improper power cable connections to the Cisco uBR10012 router

•Improper installation of other field-replaceable units (FRUs)

Table 2-5 AC-Input Power Shelf Module LEDs

LED Color Description

AC OK Green The AC-input power to the power module is present and is within the proper

range.

DC OK Green The power module is producing DC output power in the proper range.

FAULT Red This particular power module has failed and must be replaced. The 2400W

AC-input power shelf can continue operating with only two out of the three power

modules installed, but the failed module should still be replaced as soon as

possible.

36137

DC OKAC OKFAULTDC OKAC OKFAULTDC OKAC OKFAULT

DC OK AC OK FAULT

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Chapter 2 PEM Faults and Fan Assembly Failures

Fan Assembly Module Faults

Check the site for:

•Improperly grounded equipment, particularly equipment racks and power grounds

•Fluctuating voltage, which can result from excessive power drains caused by other equipment (such

as air conditioning units)

•Cable corrosion or defective power panels, circuit breakers or fuses, or cable connections

•Undersized power cables or excessive power cable lengths

•Excessive power demand on backup power systems or batteries when alternate power sources

are used

Fan Assembly Module Faults

The fan assembly module is critical to the operation of the Cisco uBR10012 router because it allows the

router to maintain proper operating temperatures. Severe overheating can result in system failure, so a

fan assembly module must always be present in the chassis while the router is operating.

Figure 2-5 shows the fan assembly module front panel and its LED indicators.

Figure 2-5 Fan Assembly Module

The Cisco uBR10012 fan assembly module contains four fans in a redundant configuration. One fan can

fail without affecting system operations. If more than one fan fails, however, the fan assembly module

must be replaced immediately to avoid overheating the system.

The fan assembly module draws air in from the bottom front of the Cisco uBR10012 router, through the

air filter at the bottom of the front bezel. The air is drawn up through the line cards, and then exits

through the vents at the top rear of the router.

Figure 2-6 shows the air circulation pattern of the Cisco uBR10012 router when two DC PEMs are

installed. The air flow when two AC PEMs are installed is similar. The front bezel is not shown for

clarity.

CISCO

10000

ETHERNET

LINK

ACTIVITY

AUX

CISCO

10000

ETHERNET

LINK

ACTIVITY

AUX

Fan

assembly

FANS OK

SINGLE FAN FAILURE

MULTIPLE FAN FAILURE

56479

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Chapter 2 PEM Faults and Fan Assembly Failures

Fan Assembly Module Faults

Figure 2-6 Fan Assembly Air Circulation Pattern

The LEDs on the front panel indicate the current status of the fans. Table 2-6 lists the fan assembly

module fault indications and recommended actions.

56430

ALARMS

CISCO

10000

FAIL

PERFORMANCE ROUTING ENGINE

CONSOLE

TUS

ACO

CRITICAL

MINOR

MAJOR

ETHERNET

LINK

ACTIVITY

AUX

SLOT 0

SLOT 1

ALARMS

CISCO

10000

FAIL

PERFORMANCE ROUTING ENGINE

CONSOLE

TUS

ACO

CRITICAL

MINOR

MAJOR

ETHERNET

LINK

ACTIVITY

AUX

SLOT 0

SLOT 1

POWER

MISWIRE

FAULT

POWER

MISWIRE

FAULT

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Chapter 2 PEM Faults and Fan Assembly Failures

Fan Assembly Module Faults

Table 2-6 Fan Assembly Module Fault Indications and Recommended Action

Symptom Steps to Take

Fans OK LED is not lit 1. Make sure the fan assembly module is fully inserted into the chassis.

2. Place your hand in front of the fan assembly module outlet to determine if the fans are

operating. If the fans are running, remove the fan assembly module and inspect the wiring

to the LEDs and fans to ensure that the wires are not nicked or cut.

3. Make sure that two AC PEM or two DC PEM modules are installed in the chassis.

Although only one PEM is required to power the chassis, two PEMs should be installed

for proper airflow. (If one PEM fails, leave the failed module in the chassis until the

replacement module can be installed.)

4. If you use DC PEMs, make sure the wiring is not reversed.

5. Replace the fan assembly module.

SINGLE FAN FAILURE

LED is lit

One fan in the fan assembly module has failed. The fan assembly can cool the chassis

sufficiently with three working fans, but replace the failed fan as soon as possible.

MULTI-FAN FAILURE LED

is lit

More than one fan has failed, and the fan assembly cannot sufficiently cool the chassis.

Replace the failed fans immediately. If necessary, power down the chassis until replacements

are available.

Fans run but the system

overheats

1. Make sure that all intake and exhaust vents on the front and rear of the chassis are free

of blockages.

2. Make sure that the ambient temperature and other environmental factors in the system

area are within the ranges specified in the “Displaying System Environment

Information” section on page 1-4.

3. Make sure all line cards and blank faceplates are in place. Make sure two PEM modules

are installed in the chassis. The cooling system cannot operate effectively unless the

chassis is fully enclosed.

4. Check the air filter, and, if necessary, clean or replace it.

5. Reduce the ambient temperature of the area surrounding the Cisco uBR10012 chassis.

This can be done using air conditioning, using fans to circulate the air in the room, and

closing the blinds on any windows that are facing the sun.

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Chapter 2 PEM Faults and Fan Assembly Failures

Fan Assembly Module Faults

CHAPTER

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Troubleshooting PRE-1 Modules

This chapter describes how to troubleshoot Performance Routing Engine (PRE-1) modules. It provides

information on troubleshooting PRE-1 fault states, the management Ethernet port, and the serial port.

•Information Required for Troubleshooting PRE-1 Modules, page 3-1

•PRE Module Not Supported, page 3-2

•PRE-1 Module Status Screen, page 3-2

•Booting Up with Redundant PRE-1 Modules, page 3-3

•PRE-1 Module Faults, page 3-4

•Ethernet Connection Problems, page 3-6

•Console Port Serial Connection Problems, page 3-7

•Troubleshooting Common System Problems, page 3-8

Information Required for Troubleshooting PRE-1 Modules

The PRE-1 module is the primary processor for the Cisco uBR10012 router, and any problems with the

PRE-1 module affect all operations. If you suspect a problem with the PRE-1 module, please collect the

following information before proceeding further, to aid in troubleshooting the problem:

Step 1 Capture all console logs and system messages.

Step 2 Capture the output of the show tech-support command. Registered users on Cisco.com can decode the

output of this command by using the Output Interpreter tool, which is at the following URL:

https://www.cisco.com/cgi-bin/Support/OutputInterpreter/home.pl

Step 3 Capture the complete bootup sequence, especially if the router is reporting errors at bootup.

Step 4 If the router is unresponsive, or if it refuses to boot to the Cisco IOS prompt, reboot the router to the

ROMMON prompt and capture a stack trace, using the stack ROMMON command. For more

information on this procedure, see the Obtaining a Stack Trace from ROM Monitor section in the

Troubleshooting Router Hangs document, at the following URL:

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a0080106fd7.shtml

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Chapter 3 Troubleshooting PRE-1 Modules

PRE Module Not Supported

The Cisco uBR10012 router supports only the PRE-1 module in Cisco IOS Release 12.2(8)BC1, and

later releases. If you attempt to boot the Cisco uBR10012 router with a PRE module with one of these

software releases, the router prints the following error message and falls through to the ROM monitor:

%%Error: PRE not supported with this image

rommon>

To correct this error, replace the PRE modules in the router with PRE-1 modules. To continue using the

original PRE modules, you must be reload the router with Cisco IOS Release 12.2(4)BC1 or an earlier

12.2 BC release.

Note For information on the replacement of PRE modules with PRE-1 modules, see the Field Notice,

Cisco uBR10000 Proactive Upgrade of PRE to PRE1, at the following URL:

http://www.cisco.com/en/US/products/hw/cable/ps2209/products_field_notice09186a00800946c5.sht

PRE-1 Module Status Screen

The PRE-1 module contains a small LED screen that displays the current state of the boot process on the

active and standby PRE-1 modules. Table 3-1 lists each message and its meaning.

Table 3-1 LED Messages on the PRE-1 Modules

Message Description

BLDRSTRT The PRE-1 module is starting the boot loader software.

BLDREXC The boot loader software has begun to execute.

BLDRMEM The boot loader software is initializing the memory on the PRE-1 module.

BLDRFILE The boot loader software is initializing the router’s file systems.

BLDRDRVR The boot loader software is initializing the driver subsystems.

BLDRLIB The boot loader software is initializing the subsystem libraries.

BLDRPROT The boot loader software is initializing the protocol subsystems.

BLDRMGMT The boot loader software is initializing the management subsystems.

BLDRINTF The boot loader software is initializing the router’s interfaces.

BLDRSTBY The boot loader software is running and the PRE-1 module is running as the

standby PRE-1 module.

LOADIOS The boot loader software has finished initializing and has begun to load the

Cisco IOS software.

IOS STRT The PRE-1 module is starting the Cisco IOS software.

IOS EXC The Cisco IOS software has begun to execute.

IOS MEM The Cisco IOS software is initializing the memory on the PRE-1 module.

IOS FILE The Cisco IOS software is initializing the router’s file systems.

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Chapter 3 Troubleshooting PRE-1 Modules

Booting Up with Redundant PRE-1 Modules

When two PRE-1 modules are installed in the Cisco uBR10012 router, the active PRE-1 module is

whichever module that first loads the Cisco IOS software and asserts control over the shared bus between

the two modules. The other PRE-1 module automatically boots the Cisco IOS software and enters the

standby mode.

Typically, the PRE-1 module in slot A (the left-most PRE-1 module slot as you face the chassis) boots

the Cisco IOS software more quickly than the PRE-1 module in slot B (the PRE-1 slot on the right). This

is because the PRE-1 module in slot B adds a slight delay in its bootup sequence, so as to allow the

module in slot A to boot first.

However, the selection of the active PRE-1 module does not affect the operations of the Cisco uBR10012

router. The router can operate normally with either the slot A or the slot B PRE-1 module acting as the

active PRE-1 module.

If you notice that the slot B PRE-1 module is always becoming the active PRE-1 module, and you would

like the slot A PRE-1 module to become the active PRE-1 module, check for the following:

•Check to see if the slot A PRE-1 module is booting Cisco IOS software from a Flash Disk in slot0

or slot1, which indicates it is using an old-style 16 or 20 MB PCMCIA card. These Flash Disk

memory cards operate more slowly than the new ATA-style 48 MB, 64 MB, or 128 MB Flash Disk

cards. If possible, boot the PRE-1 module using an ATA-style card in disk0 or disk1.

•If using an ATA-style Flash Disk is not possible, consider booting the Cisco IOS software image

from the PRE-1 module’s bootflash memory device.

IOS DRVR The Cisco IOS software is initializing the driver subsystems.

IOS LIB The Cisco IOS software is initializing the subsystem libraries.

IOS PROT The Cisco IOS software is initializing the protocol subsystems.

IOS MGMT The Cisco IOS software is initializing the management subsystems.

IOS INTF The Cisco IOS software is initializing the router’s interfaces.

IOS CONF The Cisco IOS software has begun to load the startup configuration file.

IOS RUN The Cisco IOS software is running and the PRE-1 module is running as the

active PRE-1 module. This could indicate that the PRE-1 module originally

booted up as the active module, or that a switchover put this module into the

active state.

Note This message indicates that the Cisco IOS router is running a Cisco IOS

software image. This is typically the full Cisco IOS image that was

found on a Flash disk or TFTP server. However, if an error occurs during

bootup, this could be the boot Cisco IOS image that is permanently

written in the router’s bootflash and is used when the router cannot boot

the full Cisco IOS image.

IOS STBY The Cisco IOS software is running and the PRE-1 module is running as the

standby PRE-1 module. This could indicate that the PRE-1 module originally

booted up as the standby module, or that the PRE-1 module was originally the

active PRE-1module, but that a switchover put it into the standby state.

Table 3-1 LED Messages on the PRE-1 Modules (continued)

Message Description

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Chapter 3 Troubleshooting PRE-1 Modules

PRE-1 Module Faults

•Verify that both PRE-1 modules are booting the same version of Cisco IOS software. Slight

variations in the loading of different images could allow the slot B PRE-1 module to boot first.

PRE-1 Module Faults

The PRE-1 module provides the IP routing and forwarding functionality in the Cisco uBR10012 router.

Thus, in a non-redundant PRE-1 configuration, a PRE-1 failure is a system failure. A redundant PRE-1

configuration is recommended because it allows the redundant PRE-1 module to automatically assume

full functionality upon failure of the primary PRE-1 module.

If the PRE-1 module fails, the yellow PRE-1 STATUS LED lights. If this occurs, try the following steps:

•Reboot the Cisco uBR10012 router

•Move the PRE-1 module to the other PRE-1 module slot

•Replace the PRE-1 module with a spare module

In addition, you should capture any error messages that appear on the console, as well as the state of the

PRE-1 LEDs and alphanumeric display. Then contact the Cisco Technical Assistance Center (TAC).

Figure 3-1 describes the LED indicators on the PRE-1 faceplate. Use these descriptions to verify the

operation of the PRE-1 module.

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Chapter 3 Troubleshooting PRE-1 Modules

PRE-1 Module Faults

Figure 3-1 PRE-1 Faceplate and LEDs

Table 3-2 lists the PRE-1 fault indications and recommended actions. The information contained in the

table is based on the assumption that you have a nonredundant configuration.

29995

LED Status Description

Fail

Status

Off

A major failure has disabled

the PRE.

The PRE is operating properly.

PRE is active (primary).

No power to PRE.

Off

Yellow

Green

Ethernet port LEDs

Activity

Link

Green

Off

Green

Off

Packets are being transmitted

and received.

No activity.

Carrier detected; the port is

able to pass traffic.

No carrier detected; the port is

not able to pass traffic.

PCMCIA slot 0

PCMCIA slot 1 Green

Green Slot 0 is active.

Slot 1 is active.

Critical, Major, and

Minor LEDs

Off No alarm.

–Pressing this switch disables

an audible alarm.

Alarm Cut-off (ACO)

switch

ALARMS

CISCO

10000

FAI L

PERFORMANCE ROUTING ENGINE

CONSOLE

STATUS

ACO

CRITICAL

MINOR

MAJOR

ETHERNET

LINK

ACTIVITY

AUX

SLOT 0

SLOT 1

Yellow Indicates an alarm condition.

PRE is standby (secondary).

System is booting.

Flashing

yellow

Flashing

green

Table 3-2 PRE-1 Module Fault Indications and Recommended Action

Fault Steps to Take

STATUS LED is not lit 1. Check LEDs on other modules and cards. If none are lit, refer to Table 2 -3 to

check the status of the power modules (AC PEM or DC PEM).

2. If LEDs on other modules and cards are lit, remove the card from its slot and

check for bent or broken pins on the backplane. Return the card to its slot and

screw it firmly into place.

3. Replace the card.

4. If the problem persists, contact Cisco TAC.

FAIL LED is yellow, indicating that

the PRE-1 failed

1. Reinsert the PRE-1 module.

2. Replace the module with a new PRE-1 module.

3. If the problem persists, contact Cisco TAC.

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Chapter 3 Troubleshooting PRE-1 Modules

Ethernet Connection Problems

If the management Fast Ethernet interface (F0/0/0) on the PRE-1 fails to work properly, and the

corresponding Link LED is not lit (steady green):

•Visually check that an Ethernet cable is connected to the correct Ethernet port on the

Cisco uBR10012 router.

•Verify that you are using the correct type of cable for a 100BaseT Ethernet.

•Check to see if the cable is bad or broken.

•Make sure the primary PRE-1 module booted up properly by checking the Status LED on its

faceplate. This LED on the primary PRE-1 module should be steady green. If a redundant PRE-1

module is installed, its STATUS LED should be flashing green. If this is not the case with either

PRE-1 module, remove and reinsert the module and boot it up again.

Note The show interface command also shows that there is an Ethernet interface (E0/0/0) on the PRE-1

module, but this is an internal interface that the router uses to communicate between PRE-1 modules and

line cards. This Ethernet interface is not configurable and can be used only by the router’s internal

subsystems.

If the Link LED is lit (steady green), but the Ethernet port is not working properly, make sure that the

port in question is configured properly and is not administratively shut down. If you have a working

console connection, perform the following steps:

Step 1 At the switch prompt, enter show interface fastethernet0/0/0. If the port is administratively down, enter

these commands to enable it:

c10000# configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

c10000(config)#interface fastethernet0/0/0

c10000(config-if)# no shut

c10000(config-if)# exit

c10000(config)# exit

c10000#

The PRE-1 initializes, but you cannot

establish a console connection

1. Ensure that the terminal settings are properly set.

2. If you still cannot connect, check the console cable. Is it firmly connected? Is it

the correct type of cable with proper connectors?

3. If the cable checks out and you cannot establish a console or Telnet session,

reinsert the PRE-1 module. If the problem persists, replace the PRE-1 module.

4. Enter show log to review console messages recorded in the system log.

Card cannot be fully inserted into its

slot

Make sure that you are using the correct slot (A or B) for the PRE-1 module.

An alarm LED is lit 1. Enter the show facility-alarm status command and examine the output to

determine which system component raised the alarm.

2. Troubleshoot using a procedure appropriate to the module or FRU responsible for

the alarm.

Table 3-2 PRE-1 Module Fault Indications and Recommended Action

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Chapter 3 Troubleshooting PRE-1 Modules

Console Port Serial Connection Problems

Step 2 Check that the Ethernet port in question is assigned a valid IP address.

For more information about configuring Ethernet ports, refer to the Cisco uBR10012 Universal

Broadband Router Software Configuration Guide.

If the cable, connections, power, and configuration all check out, and you still cannot connect to the

Ethernet port on the module, replace the module in question. If the problem persists, contact the Cisco

TAC for further assistance. Refer to the “Obtaining Technical Assistance” section on page x for

instructions on contacting the Cisco TAC.

Console Port Serial Connection Problems

If the console screen connected to a Cisco uBR10012 console port appears frozen or fails to work

properly, check the following steps:

Step 1 Refer to the “Cisco uBR10012 System Startup Sequence” section on page 1-5. If the display stops

responding during this process, there is no console output.

Step 2 Check the console cable and make sure it is properly connected to the console port on the active PRE-1

module at one end and to your terminal equipment or terminal server at the other end.

Note You cannot connect to the console port on the standby PRE-1 module. You must connect to

the console port on the currently active PRE-1 module. If a switchover occurs, you must

switch the serial cable to the new active PRE-1 module to maintain the console connection.

Step 3 Verify that you are using the right type of cable and adapter. For information about pin-out connections

and installation instructions, refer to the Cisco uBR10012 Universal Broadband Router Hardware

Installation Guide.

Step 4 Make sure the cable is not defective or broken. Replace the cable with another high quality cable if

possible, and check to see if the console port starts working.

Step 5 Check that the terminal equipment is configured with the correct settings for the console port. The

default console port settings are:

•9600 baud

•8 data bits

•1 stop bit

•No parity

•No flow control

Step 6 Check the LEDs on the PRE-1 faceplate to make sure it has powered up properly. If necessary, remove

and reinsert both PRE-1 modules to power them up again. Also, make sure the terminal equipment is

working properly.

Step 7 The console can appear frozen if the PRE-1 processor is busy performing other tasks, such as parsing a

large configuration file or passing a large burst of traffic. These periods are usually only temporary, and

normal reaction resumes after a few moments.

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Chapter 3 Troubleshooting PRE-1 Modules

Troubleshooting Common System Problems

Step 8 The console can be frozen if the PRE-1 process is generating a large volume of debug messages. If this

is the case, hit the return key a couple of times and type no debug all to attempt to turn off the debug

messages. This will not work if the router is in global configuration mode, but try typing do no debug

all to execute this EXEC mode command in global configuration mode.

If the cable, connections, power, and terminal settings all check out and you still cannot connect to the

console port on the module, replace the module in question. If the problem persists, contact the Cisco

TAC for further assistance.

Troubleshooting Common System Problems

This section describes how to troubleshoot the following common system problems on the

Cisco uBR10012 router:

•Troubleshooting System Crashes, page 3-8

•High CPU Utilization Problems, page 3-9

•Bus Errors, page 3-13

•Memory Problems, page 3-15

Troubleshooting System Crashes

System crashes occur when the router experiences an unexpected situation from which it cannot recover.

In response, the router stops all processes and reloads. Crashes can result from either hardware or

software problems.

When the router crashes, it is extremely important to gather as much information as possible about the

crash before doing a manual reload or power-cycling the router. All information about the crash, except

that which has been stored in the crashinfo file, is lost after a manual reload or power-cycle.

In particular, use the following commands to gather more information about the crash:

•All console, system, and message logs.

•Crashinfo file, if one was generated at the time of the crash.

•All output from the following commands:

–

show version

–

show context

–

show stacks

–

show tech-support

Note Registered Cisco.com users can decode the output of these show commands by using the Output

Interpreter tool, which is at the following URL:

https://www.cisco.com/cgi-bin/Support/OutputInterpreter/home.pl

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For additional information on troubleshooting system crashes, see the following URLs:

•Troubleshooting Router Crashes, at the following URL:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_tech_note09186a00800b4447

.shtml

•Less Common Types of System Crashes, at the following URL:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_tech_note09186a008010876d

.shtml

High CPU Utilization Problems

The PRE-1 module can experience high CPU utilization, where the CPU processor approaches 100%

usage for extended periods of time, for several reasons. See the following sections for possible causes

and solutions.

•ARP Traffic, page 3-9

•CPUHOG Errors, page 3-11

•Debug and System Messages, page 3-11

•Exec and Virtual Exec Processes, page 3-11

•Interrupts are Consuming a Large Amount of Resources, page 3-12

•Invalid Scheduler Allocate Configuration, page 3-12

•IP Input Processing, page 3-12

•One or More Processes is Consuming an Excessive Amount of Resources, page 3-12

•Problems with Access Lists, page 3-13

•SNMP Traffic, page 3-13

Also see the document Troubleshooting High CPU Utilization on Cisco Routers, which is at the

following URL:

http://www.cisco.com/en/US/products/hw/routers/ps133/products_tech_note09186a00800a70f2.shtml

ARP Traffic

High volumes of Address Resolution Protocol (ARP) requests and responses can occupy a significant

portion of the CPU time, because the router cannot use fast-switching to process ARP packets, but must

instead forward them to the route processor (RP). Because of this, processing a large volume of ARP

traffic can also prevent the router from handling normal traffic.

Theft-of-service and denial-of-service (DNS) attacks also often generate a large number of ARP packets

on the network. Many viruses also use ARP requests to discover computers that might be vulnerable to

attack, and if these computers become infected, they are used to propagate the virus, generating even

more ARP traffic on the network.

ARP requests are broadcast packets, so they are broadcast to all devices on that particular network

segment. In some cases, a router can also forward ARP broadcasts to an ARP proxy for further

processing. Some low-end routers commonly used by subscribers for home networks can also incorrectly

respond to all ARP requests, which generates even more traffic.

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In addition, the Cisco CMTS router automatically monitors ARP traffic and enters the IP addresses

found in ARP requests into its own ARP table, in the expectation that a device will eventually be found

with that IP address. Unacknowledged IP addresses remain in the router’s ARP table for 60 seconds,

which means that a large volume of ARP traffic can fill the router’s ARP table.

If ARP traffic is excessive, you can try the following ways to limit this traffic:

Step 1 Disable the forwarding of ARP requests on a cable interface by using the no cable arp command in

interface configuration mode.

Step 2 Disable the use of proxy-ARP on a cable interface by using the no cable proxy-arp command in

interface configuration mode.

Note Using the no cable arp and no cable proxy-arp commands shifts all responsibility for the

management of the IP addresses used by CMs and CPE devices to the DHCP server and

provisioning system.

Another approach would be to identify the cable modems and customer premises equipment (CPE) that

are generating the ARP traffic. A simple way of doing this is by using an access list to log requests for

an unassigned IP address in the subnet being used on a cable interface.

Step 1 Reserve at least one IP address on each cable interface’s subnet and ensure that it is not being assigned

to any cable modems or CPE devices. For example, if a cable interface is using the subnet

192.168.100.0/24, you could choose to reserve IP address 192.168.100.253 for this purpose. Ensure that

the IP addresses you have chosen are not assigned to devices by your provisioning system.

Step 2 If you currently have an access list applied to the cable interface, add a line that logs requests for this

particular IP address. If you are not currently using an access list on the cable interface, create one for

this purpose. In both cases, the relevant line would be:

Router(config)# access-list

number

permit ip any host 192.168.100.253 log

where number is the number for the access-list. Change the IP address to whatever address you have

selected to be reserved for this cable interface.

Note If you are creating a new access list, ensure that the last line of the list is access-list number

permit ip any any. Otherwise, all other traffic will be blocked on the interface.

Step 3 Apply the access list to the cable interface using the ip access-group command:

Router(config-if)# ip access-group

number

Step 4 After applying the access list, regularly examine the message log to find the devices that are attempting

to access the reserved IP address. If a cable modem or CPE device is repeatedly sending ARP requests

or replies for this IP address, it could be part of a virus or theft-of-service attack, or it could indicate a

cable modem with defective software.

Step 5 After identifying these devices, you can further investigate the matter, and if necessary, block these

devices from further network access.

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CPUHOG Errors

The router displays a %SYS-3-CPUHOG error message when a process is using an excessive amount of

processor cycles. For example, using the logging buffered command to allocate a significant amount of

memory (for example, 200 MB) for log buffers could generate a %SYS-3-CPUHOG message, because

allocating such an amount of memory requires a large amount of processor time.

For more information on what could cause this problem and how to resolve it, see the document What

Causes %SYS-3-CPUHOG Messages, at the following URL:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_tech_note09186a00800a6ac4.sht

Debug and System Messages

A large volume of debugging messages or system messages can take a significant amount of processor

time, because the PRE-1 module must spend a significant amount of time displaying these messages on

the console port. In particular, this can happen when using the verbose or detail mode of a debug

command, or if the debug command is dumping the contents of packets or packet buffers.

Use the following techniques to reduce the number of these messages:

1. Turn off the debugging messages by entering the no debug all command in privileged EXEC mode:

Router# no debug all

All possible debugging has been turned off

Router#

2. Disable console messages by using the no logging console command in global configuration mode:

Router# configure terminal

Router(config)# no logging console

Router(config)#

To keep the logging of console messages, but to limit the number of messages that can be displayed,

use the logging rate-limit command. You can rate-limit all messages (including debug messages),

or just the console messages, using one of the following commands:

Router(config)# logging rate-limit console

number-of-messages-per-second

Router(config)# logging rate-limit all

number-of-messages-per-second

3. If you have logged into the router using a Telnet connection, you can disable debug messages using

the terminal default monitor command in privileged EXEC mode:

Router# terminal default monitor

Router#

Exec and Virtual Exec Processes

The Exec process is the Cisco IOS process that handles the TTY serial lines (console, auxiliary,

asynchronous), and the Virtual Exec process handles the Virtual TTY (VTY) Telnet sessions. These

processes run as mid-level processes, so if either one is exceptionally busy, it could generate a high CPU

usage level.

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For information on resolving problems with high CPU usage caused by the Exec and Virtual EXEC

processes, see the document High CPU Utilization in Exec and Virtual Exec Processes, at the following

URL:

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2ae4.shtml

Interrupts are Consuming a Large Amount of Resources

Interrupts allow software processes to request resources when needed, as opposed to waiting for time to

be allocated to the process. If a process requests too many interrupts, however, it could impact CPU

usage, resulting in less time available to other processes.

For more information, see the document Troubleshooting High CPU Utilization Due to Interrupts, at the

following URL:

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2af0.shtml

Invalid Scheduler Allocate Configuration

The scheduler allocate command guarantees the minimum amount of time that can be allocated for

fast-switching during each network interrupt context, and the minimum amount of time that can be

allocated for non-interrupt-driven processes. An incorrect configuration for the scheduler allocate

command can cause high CPU usage, especially when too much time is allocated for non-interrupt

processes. This could result in messages such as %IPCGRP-6-NOKEEP: Too long since a keepalive

was received from the PRE.

We recommend using the default configuration, which can be restored by giving the default scheduler

allocate command in global configuration mode:

Router(config)# default scheduler allocate

Router(config)#

IP Input Processing

The Cisco IOS software uses a process named IP input to process IP packets that cannot be processed

using the fast-switching process. If the router is process-switching a lot of IP traffic, it could result in

excessively high CPU usage.

The most common reasons for excessive IP Input processing are that fast-switching has been disabled

on one or more interfaces, and that the router is receiving a large volume of traffic that must be

process-switched. For more information on resolving problems with the IP Input process, see the

Troubleshooting High CPU Utilization in IP Input Process document at the following URL:

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2af3.shtml

One or More Processes is Consuming an Excessive Amount of Resources

High CPU usage could occur if one or more processes is consuming an excessive amount of resources.

For example, the router might have an excessive number of TCP connections open, or the TTY

background process is busy displaying logging or debugging messages.

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For more information, see the document Troubleshooting High CPU Utilization Due to Processes, at the

following URL:

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00801c2af6.shtml

Problems with Access Lists

The PRE-1 module could experience high CPU usage if the router has been configured with an access

list (ACL) that is too complex or inefficiently written. Access lists are processed for top-down, starting

with the first entry in the list and continuing through each entry until a match is found. The router can

easily reach high CPU usage if it has to process dozens or hundreds of ACL entries for each packet it

receives or transmits.

To resolve the problem, reorganize the list so that the most frequently matched entries are listed first.

Also examine the list to see if multiple statements can be consolidated into a single entry. For example,

instead of listing multiple addresses on the same subnet, use one entry with a wildcard mask that matches

all of the individual addresses.

Consider using the Turbo ACL feature, which compiles the access lists so that they can be searched more

efficiently. Enable the use of Turbo ACLs by giving the access-list compiled command in global

configuration mode.

For more information on access lists, see the Configuring IP Services chapter in the IP Addressing and

Services section of the Cisco IOS IP Configuration Guide, Release 12.2, at the following URL:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipr_c/ipcprt1/1cfip.htm

Tip If you are using Ciscoworks to manage your network, consider using the Ciscoworks Access

Control List Manager to manage access lists.

SNMP Traffic

High volumes of Simple Network Management Protocol (SNMP) traffic can occupy a significant portion

of the CPU time, as the processor receives SNMP requests and sets the appropriate attributes on the

router, or sends the appropriate information back to the SNMP manager. For information on controlling

SNMP traffic, see the Application Note, IP Simple Network Management Protocol (SNMP) Causes High

CPU Utilization, at the following URL:

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a00800948e6.shtml

Bus Errors

Bus errors occur when the router tries to access a memory location that either does not exist (which

indicates a software error) or that does not respond (which indicates a hardware error). Bus errors

generated by the PRE-1 module typically cause a crash and force the router to reload.

Use the following procedure to determine the cause of a bus error and to resolve the problem. Perform

these steps as soon as possible after the bus error, before manually reloading or power cycling the router.

Step 1 Use the show version command to display the reason for the last system reload:

Router# show version

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Cisco Internetwork Operating System Software

IOS (tm) 10000 Software (UBR10K-P6-M), Experimental Version 12.2(20031215:22350]

Compiled Mon 15-Dec-03 17:28 by mnagai

Image text-base: 0x60008968, data-base: 0x61B80000

ROM: System Bootstrap, Version 12.0(9r)SL2, RELEASE SOFTWARE (fc1)

BOOTLDR: 10000 Software (C10K-EBOOT-M), Version 12.0(17)ST, EARLY DEPLOYMENT RE)

ubr10k uptime is 6 days, 18 hours, 59 minutes

System returned to ROM by bus error at PC 0x0, address 0x0 at 04:15:55 UTC Thu Dec 11 2003

System restarted at 04:18:56 UTC Thu Dec 11 2003

...

Router#

Step 2 Determine whether the memory address for the bus error is a valid address. If the address is valid, the

problem is most likely a hardware problem. If the address is an invalid address (such as the above

example of 0x0), the problem is software-related.

Step 3 If the problem is hardware-related, you can map the memory address to a particular hardware component

by using the show region command.

Router# show region

Region Manager:

Start End Size(b) Class Media Name

0x0A000000 0x0FFFFFFF 100663296 Iomem R/W iomem

0x2A000000 0x2FFFFFFF 100663296 Iomem R/W iomem:(iomem_cwt)

0x60000000 0x69FFFFFF 167772160 Local R/W main

0x60008968 0x61B7FFFF 28800664 IText R/O main:text

0x61B80000 0x61CC1ADF 1317600 IData R/W main:data

0x61CC1AE0 0x627663BF 11159776 IBss R/W main:bss

0x627663C0 0x69FFFFFF 126458944 Local R/W main:heap

0x70000000 0x7FFFFFFB 268435452 Local R/W heap2

0x80000000 0x89FFFFFF 167772160 Local R/W main:(main_k0)

0xA0000000 0xA9FFFFFF 167772160 Local R/W main:(main_k1)

Router#

Step 4 When you have identified the hardware that is generating the bus error, try removing and reinserting the

hardware into the chassis. If this does not correct the problem, replace the DRAM chips on the hardware.

If the problem persists, replace the hardware.

Step 5 If the problem is software-related, verify that you are running a released version of software, and that

this release of software supports all of the hardware that is installed in the router. If necessary, upgrade

the router to the latest version of software.

Step 6 To further troubleshoot the problem, registered users on Cisco.com can also decode the output of

multiple show commands by using the Output Interpreter tool, which is at the following URL:

https://www.cisco.com/cgi-bin/Support/OutputInterpreter/home.pl

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Tip The most effective way of using the Output Interpreter tool is to capture the output of the

show stacks and show tech-support commands and upload the output into the tool. If the

problem appears related to a line card, you can also try decoding the show context command.

For more information on troubleshooting bus errors, see the Troubleshooting Bus Error Crashes

document, at the following URL:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_tech_note09186a00800cdd51.sht

Memory Problems

This section describes the following types of memory problems:

•Alignment Errors, page 3-15

•Low Memory Errors, page 3-16

•Memory Parity Errors, page 3-16

•Particle Pool Fallbacks, page 3-17

•Spurious Interrupts, page 3-18

•Spurious Memory Accesses, page 3-19

Alignment Errors

Alignment errors occur when the software attempts to read or write data using a data size that is not

aligned with the memory address being used. For example, an alignment error occurs when attempting

to read two bytes from a memory address that is not an even multiple of two bytes.

Alignment errors are always caused by a software bug, and can be either correctable or fatal. See the

following sections for more information. Also see the document Troubleshooting Spurious Accesses,

Alignment Errors, and Spurious Interrupts, at the following URL:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_tech_note09186a00800a65d1.sht

Correctable Alignment Errors

The Cisco IOS software can automatically correct most alignment errors. When it does so, the router

generates a system error message similar to the following:

%ALIGN-3-CORRECT: Alignment correction made at 0x60262478 reading/writing 0x60A9FF5C

Occasional alignment errors do not necessarily require operator intervention, because the Cisco IOS

software can correct these errors and continue with normal operations. However, correcting alignment

errors consumes processor resources and could impact performance if the errors continuously repeat.

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Fatal Alignment Errors

If the alignment error was a fatal error, it displays a message similar to the following:

%ALIGN-1-FATAL: Corrupted program counter error.

ERROR: Slot 0, NPE300/IOFE2/VXR, CACHE, External Data Cache Memory Test:

*** Data Expected= 0x99999999 ***

Fatal alignment errors are most likely a hardware fault on the processor card. The card itself could be

faulty, or the memory on the card could be faulty. Try replacing the processor card and rebooting the

router. If a replacement card is not available, try replacing the memory on the processor card, making

sure that the new memory meets the specifications that are required by the card.

Low Memory Errors

The router can experience low memory errors for a number of reasons, including the following possible

causes:

•The router is handling an excessively large volume of traffic. In particular, the router could be

experiencing a large volume of traffic that requires special handling, such as ARP requests.

•Abnormal processes are using excessive amounts of memory.

•Large amounts of memory are still allocated to dead processes.

•Software errors could have resulted in memory leaks.

•Hardware problems with the memory on the processor card or line card.

•Hardware problems on the processor card or line card.

Low memory problems are usually indicated by one or more system messages (for example,

SYS-2-MALLOCFAIL). For troubleshooting steps to resolve problems with low memory, see the Tech

Note titled Troubleshooting Memory Problems, at the following URL:

http://www.cisco.com/warp/customer/63/mallocfail.shtml

Memory Parity Errors

A memory parity error means that one or more bits at a memory location were unexpectedly changed

after they were originally written. This error could indicate a potential problem with the Dynamic

Random Access Memory (DRAM) that is onboard the PRE-1 module.

Parity errors are not expected during normal operations and might force the router to reload. If the router

did reload because of a parity error, the show version command displays a message such as “System

restarted by processor memory parity error” or “System restarted by shared memory parity error.” For

example:

Router# show version

Cisco Internetwork Operating System Software

IOS (tm) 10000 Software (UBR10K-P6-M), Experimental Version 12.2(20031215:22350]

Compiled Mon 15-Dec-03 17:28 by mnagai

Image text-base: 0x60008968, data-base: 0x61B80000

ROM: System Bootstrap, Version 12.0(9r)SL2, RELEASE SOFTWARE (fc1)

BOOTLDR: 10000 Software (C10K-EBOOT-M), Version 12.0(17)ST, EARLY DEPLOYMENT RE)

ubr10k uptime is 6 days, 18 hours, 59 minutes

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System returned to ROM by processor memory parity error at PC 0x60301298, address 0x0 at

17:19:47 PDT Mon Dec 15 2003

System restarted at 17:19:47 PDT Mon Dec 15 2003

...

Router#

Parity errors can be categorized in two different ways:

•Soft parity errors occur when an energy level within the DRAM memory changes a bit from a one

to a zero, or a zero to a one. Soft errors are rare and are most often the result of normal background

radiation. When the CPU detects a soft parity error, it attempts to recover by restarting the affected

subsystem, if possible. If the error is in a portion of memory that is not recoverable, it could cause

the system to crash. Although soft parity errors can cause a system crash, you do not need to swap

the board or any of the components, because the problem is not defective hardware.

•Hard parity errors occur when a hardware defect in the DRAM or processor board causes data to be

repeatedly corrupted at the same address. In general, a hard parity error occurs when more than one

parity error in a particular memory region occurs in a relatively short period of time (several weeks

to months).

When parity occurs, take the following steps to resolve the problem:

Step 1 Determine whether this is a soft parity error or a hard parity error. Soft parity errors are 10 to 100 times

more frequent than hard parity errors. Therefore, wait for a second parity error before taking any action.

Monitor the router for several weeks after the first incident, and if the problem reoccurs, assume that the

problem is a hard parity error and proceed to the next step.

Step 2 When a hard parity error occurs (two or more parity errors at the same memory location), try removing

and reinserting the PRE-1 module, making sure to fully insert the card and to securely tighten the

restraining screws on the front panel.

Step 3 If this does not resolve the problem, remove and reseat the DRAM chips. If the problem continues,

replace the DRAM chips.

Step 4 If parity errors occur, the problem is either with the PRE-1 module or the router chassis. Replace the

PRE-1 module.

Step 5 If the problems continue, contact Cisco TAC for further instructions.

For more information about parity errors, see the Processor Memory Parity Errors document, at the

following URL:

http://www.cisco.com/en/US/products/hw/routers/ps341/products_tech_note09186a0080094793.shtml

Particle Pool Fallbacks

Private particle pools are buffers in I/O memory that store packets while they are being processed. The

Cisco IOS software allocates a fixed number of private particle pools during system initialization, and

these buffers are reserved for packet use, so as to minimize system contention for memory resources.

The system uses buffer control structures called “rings” to manage the entries in the particle pools. Each

ring is a circular linked-list of pointers to each packet in the particle pool. The system creates a pair of

rings for each interface, with one ring for packets waiting to be transmitted and another ring for packets

that are being received.

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The system also allocates public pools in a number of different sizes for more general use. If a packet

requires special handling, or if a packet cannot be completely processed at interrupt time, the system

copies the packet into a portion of contiguous memory in the public pool, so it can be processed

switched.

Tip Use the show buffers command to display the current status of the router’s particle pools.

Fallbacks with particle pools occur when bursts of traffic produce more packets than would fit in the

available buffer space. When an interface runs out of space in the private particle pools, it falls back to

using the normal public memory. Fallbacks are expected during periods of bursty traffic, and the router

should be considered to be operating normally in these situations.

If fallbacks occur more frequently, however, it could indicate a problem. In particular, if the private

particle pools are consistently producing fallbacks, it could result in the router using excessive amounts

of public memory for packet processing, reducing the resources that are available to the other router

processes. If this is the case, look for the following possible causes.

•Extremely fast interfaces are handling large volumes of traffic with a high rate of throughput that is

approaching the maximum rate on the interface.

•The Fast Ethernet interfaces on the processor card could be heavily loaded.

•The Cisco IOS software has a memory leak that is not releasing the memory in the private particle

pool after the interface has finished processing a packet.

For more information on resolving problems with particle pool buffers, see the document Buffer Tuning,

at the following URL:

http://www.cisco.com/warp/public/63/buffertuning.html

Also see the document Troubleshooting Buffer Leaks, at the following URL:

http://www.cisco.com/warp/public/63/bufferleak_troubleshooting.html

Spurious Interrupts

A spurious interrupt occurs when the Cisco IOS software generates an unnecessary interrupt for packet

that has been processed already. This is a software error that is usually caused by an improper

initialization of interrupt handling routines, or by a race condition where two processes compete to

handle the same process.

Spurious interrupts can occasionally be expected during normal operations, and the occasional spurious

interrupt has no discernible impact on the router’s performance. However, action might be needed if the

number of spurious interrupts is high or increasing, and performance is being degraded, with packets

being dropped.

For information on resolving the problem with spurious interrupts, see the document Troubleshooting

Spurious Accesses, Alignment Errors, and Spurious Interrupts, at the following URL:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_tech_note09186a00800a65d1.sht

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Spurious Memory Accesses

A spurious memory access occurs when a Cisco IOS software process attempts to access memory in the

lowest 16 KB region of memory, which is a restricted location. Typically, such errors display a system

error message similar to the following:

%ALIGN-3-SPURIOUS: Spurious memory access made at 0x60968C44 reading 0x0

%ALIGN-3-TRACE: -Traceback= 60968C44 60269808 602389D8 00000000 00000000 00000000

00000000 00000000

Where possible, the Cisco IOS software handles spurious memory accesses by returning a value of zero

to the calling routine, and then displaying the above error message. If this is not possible, the router

crashes with a Segment Violation (SegV) error. In either case, the cause of the error is almost always a

bug in the Cisco IOS software.

If possible, upgrade to the latest release of the Cisco IOS software. If the bug still exists on the router,

see the section Spurious Accesses in the document Troubleshooting Spurious Accesses, Alignment

Errors, and Spurious Interrupts, at the following URL:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_tech_note09186a00800a65d1.sht

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Troubleshooting Line Cards

This chapter discusses troubleshooting faults on the following Cisco uBR10012 line cards:

•General Information for Troubleshooting Line Card Crashes, page 4-2

•Troubleshooting the Timing, Communication, and Control Plus Card, page 4-8

•Troubleshooting the OC-12 Packet-Over-SONET Line Card, page 4-12

•Troubleshooting the OC-12 Dynamic Packet Transport Spatial Reuse Protocol WAN Card, page

4-14

•Troubleshooting the Cisco uBR10012 OC-48 DPT/POS Line Card, page 4-16

•Troubleshooting the Gigabit Ethernet Line Card, page 4-18

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General Information for Troubleshooting Line Card Crashes

Line card crashes occur when the hardware or software encounter unexpected situations that are not

expected in the current design. As a general rule, they usually indicate a configuration error, a software

error, or a hardware problem.

Table 4-1 lists the show commands that are most useful in collecting information to troubleshoot line

card crashes.

Use the following procedure if you suspect that a line card has crashed.

Step 1 If you can identify the particular card that has crashed or is experiencing problems, first use the other

sections in this chapter to perform basic troubleshooting. In particular, ensure that the line card is fully

inserted into the proper slot, and that all cables are properly connected.

Step 2 If any system messages were displayed on the console or in the SYSLOG logs at the time of the crash,

consult the Cisco CMTS System Messages guide and the Cisco IOS System Messages Guide for possible

suggestions on the source of the problem.

Step 3 Line cards can crash or appear to crash when an excessive number of debug messages are being

generated. In particular, this can happen when using the verbose or detail mode of a debug command,

or if the debug command is dumping the contents of packets or packet buffers. If the console contains a

large volume of debug output, turn off all debugging with the no debug all command.

Step 4 If the system message log contains messages that indicate the line card is not responding (for example,

%IPCOIR-3-TIMEOUT), and the card’s LEDs are not lit, the line card might have shut down because of

overheating. Ensure that all chassis slots either have the proper card or module installed in them. If a slot

is blank, ensure that the slot has a blank front panel installed, so that proper airflow and cooling can be

maintained in the chassis.

Step 5 Use the show context summary command to identify all of the line cards that have experienced a crash:

Router# show context summary

CRASH INFO SUMMARY

Slot 1/0: 0 crashes

Slot 1/1: 0 crashes

Slot 2/0: 0 crashes

Slot 2/1: 0 crashes

Slot 3/0: 0 crashes

Slot 3/1: 0 crashes

Slot 4/0: 1 crashes

1 - crash at 04:28:56 EDT Tue Apr 20 1999

Slot 4/1: 0 crashes

Slot 5/0: 0 crashes

Table 4-1 Relevant Show Commands for Line Card Crashes

Command Description

show version Provides general information about the system's hardware and software

configurations

show logging Displays the general logs of the router

show diag [slot/subslot] Provides specific information about a particular slot: type of engine,

hardware revision, firmware revision, memory configuration, and so on.

show context [summary |

slot [slot/subslot] ]

Provides context information about the most recent crashes. This is

often the most useful command for troubleshooting line card crashes.

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Chapter 4 Troubleshooting Line Cards

General Information for Troubleshooting Line Card Crashes

Slot 5/1: 0 crashes

Slot 6/0: 0 crashes

Slot 6/1: 0 crashes

Slot 7/0: 0 crashes

Slot 7/1: 0 crashes

Slot 8/0: 0 crashes

Slot 8/1: 0 crashes

Router#

Step 6 After identifying the particular card that crashed, use the show context command again to display more

information about the most recent crash. For example:

Router# show context slot 2/0

CRASH INFO: Slot 2/0, Index 1, Crash at 19:57:56 PDT Wed Nov 27 2002

VERSION:

7200 Software (UBR10KCLC-LCK8-M), Version 12.2(122BC.021127.), CISCO DEVELOPMENN

Compiled Wed 27-Nov-02 12:57 by

Card Type: UNKNOWN, S/N CAB0544L6F5

System exception: sig=10, code=0x8000000C, context=0x60A1BDE4

STACK TRACE:

traceback 601C28FC 601C29B4 601B9E8C 600F99B0 600F999C

CONTEXT:

$0 : 00000000, AT : 60930000, v0 : FFFFFFFF, v1 : 60940000

a0 : 00000000, a1 : 00000000, a2 : 00000001, a3 : 0000EA60

t0 : FFFFFFFF, t1 : FFFFA91C, t2 : 601284E0, t3 : FFFF00FF

t4 : 601284D8, t5 : 00000062, t6 : 00000000, t7 : D1B71759

s0 : 00000000, s1 : 00000008, s2 : 00000000, s3 : 60CD0998

s4 : 60CD0990, s5 : 00000000, s6 : 00000002, s7 : 60940000

t8 : 60D98C2C, t9 : 0000001B, k0 : 3040D001, k1 : BE840244

gp : 6093BD60, sp : 60CD0968, s8 : 60A70000, ra : 601C2900

EPC : 0x601C28F8, SREG : 0x3400F903, Cause : 0x8000000C

ErrorEPC : 0xCF1998F2

SLOT 2/0: *Jan 1 00:01:30.371: %SYS-2-EXCEPTIONDUMP: System Crashed, Writing Coredump...

Router#

Step 7 Look for the SIG Type in the line that starts with “System exception” to identify the reason for the crash.

Table 4-2 lists the most common SIG error types and their causes.

Ta b l e 4 - 2 S I G Va l u e Ty p e s

SIG Value SIG Name Error Reason

SIGINT Unexpected hardware interrupt

3 SIGQUIT Abort due to break key

4 SIGILL Illegal opcode exception

5 SIGTRAP Abort due to Break Point or an arithmetic exception

8 SIGFPE Floating point unit (FPU) exception

9 SIGKILL Reserved exception

10 SIGBUS Bus error exception

11 SIGSEGV SegV exception

20 SIGCACHE Cache parity exception

21 SIGWBERR Write bus error interrupt

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General Information for Troubleshooting Line Card Crashes

Step 8 The vast majority of line card crashes are either Cache Parity Exception (SIG type=20), Bus Error

Exception (SIG type=10), and Software-forced Crashes (SIG type=23). Use the following sections to

further troubleshoot these problems:

•Cache Parity Errors, page 4-4

•Bus Errors, page 4-5

•Software-Forced Crashes, page 4-6

If the line card crashed for some other reason, capture the output of the show tech-support command.

Registered Cisco.com users can decode the output of this command by using the Output Interpreter tool,

which is at the following URL:

https://www.cisco.com/cgi-bin/Support/OutputInterpreter/home.pl

Step 9 If you cannot resolve the problem using the information from the Output Interpreter, collect the

following information and contact Cisco TAC:

•All relevant information about the problem that you have available, including any troubleshooting

you have performed.

•Any console output that was generated at the time of the problem.

•Output of the show tech-support command.

•Output of the show log command (or the log that was captured by your SYSLOG server, if

available).

For information on contacting TAC and opening a case, see the “Obtaining Technical Assistance” section

on page x.

Cache Parity Errors

A cache parity error (SIG type is 20) means that one or more bits at a memory location were

unexpectedly changed after they were originally written. This error could indicate a potential problem

with the Dynamic Random Access Memory (DRAM) that is onboard the line card.

Parity errors are not expected during normal operations and could force the line card to crash or reload.

These memory errors can be categorized in two different ways:

•Soft parity errors occur when an energy level within the DRAM memory changes a bit from a one

to a zero, or a zero to a one. Soft errors are rare and are most often the result of normal background

radiation. When the CPU detects a soft parity error, it attempts to recover by restarting the affected

subsystem, if possible. If the error is in a portion of memory that is not recoverable, it could cause

the system to crash. Although soft parity errors can cause a system crash, you do not need to swap

the board or any of the components, because the problem is not defective hardware.

22 SIGERROR Fatal hardware error

23 SIGRELOAD Software-forced crash

Ta b l e 4 - 2 S I G Va l u e Ty p e s

SIG Value SIG Name Error Reason

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•Hard parity errors occur when a hardware defect in the DRAM or processor board causes data to be

repeatedly corrupted at the same address. In general, a hard parity error occurs when more than one

parity error in a particular memory region occurs in a relatively short period of time (several weeks

to months).

When parity occurs, take the following steps to resolve the problem:

Step 1 Determine whether this is a soft parity error or a hard parity error. Soft parity errors are 10 to 100 times

more frequent than hard parity errors. Therefore, wait for a second parity error before taking any action.

Monitor the router for several weeks after the first incident, and if the problem reoccurs, assume that the

problem is a hard parity error and proceed to the next step.

Step 2 When a hard parity error occurs (two or more parity errors at the same memory location), try removing

and reinserting the line card, making sure to fully insert the card and to securely tighten the restraining

screws on the front panel.

Step 3 If this does not resolve the problem, remove and reseat the DRAM chips. If the problem continues,

replace the DRAM chips.

Step 4 If parity errors occur, the problem is either with the line card or the router chassis. Try removing the line

card and reinserting it. If the problem persists, try removing the line card from its current slot and

reinserting it in another slot, if one is available. If that does not fix the problem, replace the line card.

Step 5 If the problems continue, collect the following information and contact Cisco TAC:

•All relevant information about the problem that you have available, including any troubleshooting

you have performed.

•Any console output that was generated at the time of the problem.

•Output of the show tech-support command.

•Output of the show log command (or the log that was captured by your SYSLOG server, if

available).

For information on contacting TAC and opening a case, see the “Obtaining Technical Assistance” section

on page x.

Bus Errors

Bus errors (SIG type is 10) occur when the line card tries to access a memory location that either does

not exist (which indicates a software error) or that does not respond (which indicates a hardware error).

Use the following procedure to determine the cause of a bus error and to resolve the problem.

Perform these steps as soon as possible after the bus error. In particular, perform these steps before

manually reloading or power cycling the router, or before performing an Online Insertion/Removal

(OIR) of the line card, because doing so eliminates much of the information that is useful in debugging

line card crashes.

Step 1 Capture the output of the show stacks, show context, and show tech-support commands. Registered

Cisco.com users can decode the output of this command by using the Output Interpreter tool, which is

at the following URL:

https://www.cisco.com/cgi-bin/Support/OutputInterpreter/home.pl

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General Information for Troubleshooting Line Card Crashes

Step 2 If the results from the Output Interpreter indicate a hardware-related problem, try removing and

reinserting the hardware into the chassis. If this does not correct the problem, replace the DRAM chips

on the hardware. If the problem persists, replace the hardware.

Step 3 If the problem appears software-related, verify that you are running a released version of software, and

that this release of software supports all of the hardware that is installed in the router. If necessary,

upgrade the router to the latest version of software.

Tip The most effective way of using the Output Interpreter tool is to capture the output of the

show stacks and show tech-support commands and upload the output into the tool. If the

problem appears related to a line card, you can also try decoding the show context command.

Upgrading to the latest version of the Cisco IOS software eliminates all fixed bugs that can cause line

card bus errors. If the crash is still present after the upgrade, collect the relevant information from the

above troubleshooting, as well as any information about recent network changes, and contact Cisco TAC.

Software-Forced Crashes

Software-forced crashes (SIG type is 23) occur when the Cisco IOS software encounters a problem with

the line card and determines that it can no longer continue, so it forces the line card to crash. The original

problem could be either hardware-based or software-based.

The most common reason for a software-forced crash on a line card is a “Fabric Ping Timeout,” which

occurs when the PRE-1 module sends five keepalive messages (fabric pings) to the line card and does

not receive a reply. If this occurs, you should see error messages similar to the following in the router’s

console log:

%GRP-3-FABRIC_UNI: Unicast send timed out (4)

%GRP-3-COREDUMP: Core dump incident on slot 4, error: Fabric ping failure

Fabric ping timeouts are usually caused by one of the following problems:

•High CPU Utilization—Either the PRE-1 module or line card is experiencing high CPU utilization.

The PRE-1 module or line card could be so busy that either the ping request or ping reply message

was dropped. Use the show processes cpu command to determine whether CPU usage is

exceptionally high (at 95 percent or more). If so, see the “High CPU Utilization Problems” section

on page 3-9 for information on troubleshooting the problem.

•CEF-Related Problems—If the crash is accompanied by system messages that begin with “%FIB,”

it could indicate a problem with Cisco-Express Forwarding (CEF) on one of the line card’s

interfaces. For more information, see Troubleshooting CEF-Related Error Messages, at the

following URL:

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a0080110d68.s

html

•IPC Timeout—The InterProcess Communication (IPC) message that carried the original ping

request or the ping reply was lost. This could be caused by a software bug that is disabling interrupts

for an excessive period of time, high CPU usage on the PRE-1 module, or by excessive traffic on the

line card that is filling up all available IPC buffers.

If the router is not running the most current Cisco IOS software, upgrade the router to the latest

software release, so that any known IPC bugs are fixed. If the show processes cpu shows that CPU

usage is exceptionally high (at 95 percent or more), or if traffic on the line card is excessive, see the

“High CPU Utilization Problems” section on page 3-9.

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General Information for Troubleshooting Line Card Crashes

If the crash is accompanied by %IPC-3-NOBUFF messages, see Troubleshooting IPC-3-NOBUFF

Messages on the Cisco 12000, 10000 and 7500 Series, at the following URL:

http://www.cisco.com/en/US/products/hw/routers/ps133/products_tech_note09186a00800945a1.s

html

•Hardware Problem—The card might not be fully inserted into its slot, or the card hardware itself

could have failed. In particular, if the problem began occurring after the card was moved or after a

power outage, the card could have been damaged by static electricity or a power surge. Only a small

number of fabric ping timeouts are caused by hardware failures, so check for the following before

replacing the card:

–

Reload the software on the line card, using the hw-module slot reset command.

–

Remove and reinsert the line card in its slot.

–

Try moving the card to another slot, if one is available.

If software-forced crashes continue, collect the following information and contact Cisco TAC:

•All relevant information about the problem that you have available, including any troubleshooting

you have performed.

•Any console output that was generated at the time of the problem.

•Output of the show tech-support command.

•Output of the show log command (or the log that was captured by your SYSLOG server, if

available).

For information on contacting TAC and opening a case, see the “Obtaining Technical Assistance” section

on page x.

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Chapter 4 Troubleshooting Line Cards

Troubleshooting the Timing, Communication, and Control Plus Card

Troubleshooting the Timing, Communication, and Control Plus

Card

At least one working Timing, Communication, and Control Plus (TCC+) card must be installed in the

Cisco uBR10012 router for normal operations. The TCC+ card acts as a secondary processor that

performs the following functions:

•Generates and distributes 10.24 MHz clock references to each cable interface line card.

•Generates and distributes 32-bit time stamp references to each cable interface line card.

•Allows software to independently power off any or all cable interface line cards.

•Provides support for Online Insertion/Removal (OIR) operations of line cards.

•Drives the LCD panel used to display system configuration and status information.

•Monitors the supply power usage of the chassis.

•Provides two redundant RJ-45 ports for external timing clock reference inputs such as a Global

Positioning System (GPS) or BITS clock.

If the Cisco uBR10012 router does not have a working TCC+ card installed, the WAN and cable interface

line cards will experience excessive packet drops, or all traffic will be dropped, because of an invalid

timing signal. Also, if no TCC+ card is installed, the cable power command is disabled, because this

function is performed by the TCC+ card.

Note Because the TCC+ card is considered a half-height card, use slot numbers 1/1 or 2/1 to display

information for the TCC+ card using the show diag command. The show cable clock and show

controllers clock-reference commands also use these slot numbers when displaying clock-related

information.

Figure 4-1 TCC+ Front Panel

The front panel on the TCC+ card has seven LEDs. Table 4-3 describes each LED on the TCC+ card.

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Troubleshooting the Timing, Communication, and Control Plus Card

When performing any troubleshooting on the TCC+ cards, first check the LEDs as follows:

1. Check the POWER LEDs on each TCC+ card. Are the POWER LEDs on each TCC+ card on

(green)?

–

If no, remove the TCC+ card and reinsert it, making sure that it firmly connects to the backplane

and that both captive screws are tightly connected.

–

If yes, proceed to the next step.

2. Is the STATUS LED on the primary TCC+ card on (green) to indicate that it is the primary card? Is

the STATUS LED on the secondary TCC+ card flashing (green) to indicate that it is the redundant

card?

Use Table 4-4 to continue troubleshooting the TCC+ cards.

Table 4-3 TCC+ Card LEDs and Their Functions

LED Status Description

POWER Green

Off

Indicates that power is supplied to the TCC+ card.

Power is off.

STATUS- bi-color Yellow

Green

Blinking

Green

Indicates that the CPU is in the bootup process, self-test, or downloading code.

Indicates that the CPU has successfully completed the boot, self-test, and code

download process, and that the TCC+ card is the active card.

Indicates that the CPU has successfully completed the boot, self-test, and code

download process, and that the TCC+ card is the backup card.

MAINTENANCE Off

Yellow

Normally off. Indicates that no maintenance action is required.

Indicates a required maintenance operation and that the TCC+ card can be

hot-swapped.

PRESENT (Primary) Green

Off

Normally on. Indicates that a valid clock reference signal is present at the associated

input.

Indicates that no signal is present, or that the TCC+ card is unable to synchronize to

the signal at the associated input.

ACTIVE (Primary) Green

Off

Normally on. Indicates that the associated input has been selected as the active clock

reference for the TCC+ card.

Indicates that the associated input is not the active clock reference.

PRESENT (Secondary) Green

Off

Normally on. Indicates that a valid clock reference signal is present at the associated

input.

Indicates that no signal is present, or that the TCC+ card is unable to synchronize to

the signal at the associated input.

ACTIVE (Secondary) Green

Off

Normally on. Indicates that the associated input has been selected as the active clock

reference for the TCC+ card.

Indicates that the associated input is not the active clock reference.

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Troubleshooting the Timing, Communication, and Control Plus Card

Table 4-4 TCC+ Card Faults and Recommended Responses

Fault Type Response

The show cable clock command shows that no

TCC+ cards are installed:

Router# show cable clock

Number of TCCplus Cards in the Chassis: 0

TCCplus Cards are not yet configured

Router#

The console also typically displays the error

message %UBR10KTCC-1-NOTCC: No working

TCCplus card available in the system.

1. Verify that at least one TCC+ card is installed in the chassis. If not,

install a TCC+ card, because it is required for normal operations.

2. If only one TCC+ card is installed, it might not have been properly

initialized, so remove it from its slot, wait approximately 30 seconds,

and reinsert it.

3. If only one TCC+ card is installed, its slot might be fault, so remove

the card from its slot and install it in the other TCC+ card slot.

4. Replace the TCC+ card with a known, working TCC+ card.

An IPC error message (IPCGRP-3-SYSCALL)

occurs for the TCC+ card slots (slot 1/1 or slot

2/1).

1. If this message results after a line card is reset using the hw-module

reset command, it is an informational-only message that indicates

only that an IPC message was missed while the processor was

performing the reset of the line card. This error message can be

ignored.

2. Upgrade the Cisco uBR10012 router to Cisco IOS Release

12.2(11)BC2 or later release.

The console displays the following error message:

%UBR10KTCC-1-BADTCC: TCCplus card in

slot put under maintenance: reason

The Cisco uBR10012 router detected that the TCC+ card in the indicated

slot was faulty. If a redundant card is installed, the system passed control

to it. The faulty TCC+ card has been put into maintenance mode. The

following errors are possible:

•Holdover rcvd by Active Card—The active TCC+ card generated a

holdover interrupt to indicate an error in its clock source.

•Holdover rcvd by Backup Card—The backup TCC+ card generated a

holdover interrupt to indicate an error in the clock source being

received by either the Active or Backup card.

•Bad Clock reported by CLC(s)—A cable interface line card reported

that the clock signal being received from the TCC+ card is faulty.

•TRU Loss of Sync—The clock hardware on the TCC+ card reported a

•Unknown—An unknown failure occurred, possibly a hardware

failure.

To correct the problem:

1. If an external clock source is being used, check that the clock source

is valid national clock source, such as a GPS receiver or BITS clock.

2. If the clock source is valid, remove and reinsert the faulty TCC+ card.

3. If the MAINTENANCE LED on the faulty TCC+ card is still lit,

replace the card.

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Troubleshooting the Timing, Communication, and Control Plus Card

The show controllers clock-reference command

displays compare errors between the two TCC+

cards installed in the Cisco uBR10012 router.

1. If this occurs at system startup or only occasionally at other times,

this error can be ignored, because the system typically records a

slight delay when the TCC+ cards synchronize with each other. These

initial compare errors can be ignored and cleared with the cable

clock clear-counters command.

2. If this error repeatedly occurs, it could indicate a hardware problem

with one of the TCC+ cards. Try replacing each card to see if the

problem disappears.

The show controllers command for a cable

interface displays the message “Timestamp is

from local oscillator.” This command should

show that the timestamp is coming either from an

external source or from the TCC+ card.

1. Verify that at least one TCC+ card is installed in the chassis. If not,

install a TCC+ card.

2. Verify that a valid national clock source, such as a GPS receiver or

BITS clock, is plugged into the TCC+ card’s RJ-45 connector.

3. Replace the TCC+ card.

Table 4-4 TCC+ Card Faults and Recommended Responses

Fault Type Response

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Chapter 4 Troubleshooting Line Cards

Troubleshooting the OC-12 Packet-Over-SONET Line Card

Figure 4-2 describes the LEDs on the Cisco uBR10-1OC12/P-SMI OC-12 Packet-Over-SONET (POS)

line card faceplate. Use these descriptions to verify the operation of the OC-12 POS line card.

Figure 4-2 OC-12 POS Line Card LEDs

Table 4-5 describes fault conditions on the OC-12 POS line card and recommended corrective actions.

29993

LED Status Description

Fail

Rx (receive)

Tx (transmit)

Carrier

Yellow

Off

Green

A major failure has disabled the

line card.

The line card is operating

properly.

Receiving traffic.

Carrier detected.

Carrier not detected.

Off

Yellow

Not receiving traffic.

Green Transmitting traffic.

Not transmitting traffic.

Green

CISCO

10000

CARRIER

FAIL

OC–12/STM–4 POS SM–IR

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Troubleshooting the OC-12 Packet-Over-SONET Line Card

Table 4-5 OC-12 POS Line Card Fault Indications and Recommended Action

Fault Corrective Action

Fail LED is lit indicating that the line card has failed 1. Reinsert the line card.

2. Replace the line card.

3. Insert the line card in another slot.

4. Contact the Cisco TAC.

Carrier LED is off and interface is enabled 1. Check the fiber optic cable, making sure that it is properly

attached at both ends.

2. Make sure that you are using the proper fiber type.

3. Check the cable connections on the remote equipment.

4. Contact the Cisco TAC.

Fail LED blinks then lights steadily repeatedly

Card seems to be passing traffic (Tx/Rx lights), but

cannot communicate with the PRE

1. Check for bent pins on the backplane.

2. If there are no bent pins, replace with a new line card.

3. Try inserting the line card in a different slot.

If the card works in a different slot, the Cisco uBR10012

backplane may be defective. Contact the Cisco TAC.

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Chapter 4 Troubleshooting Line Cards

Troubleshooting the OC-12 Dynamic Packet Transport Spatial Reuse Protocol WAN Card

Troubleshooting the OC-12 Dynamic Packet Transport Spatial

Reuse Protocol WAN Card

Figure 4-3 shows and Table 4-6 describes the LEDs on the Cisco BR10-SRP-OC12SML Dynamic

Packet Transport (DPT) Spatial Reuse Protocol (SRP) WAN card.

Figure 4-3 OC12 SRP/DPT WAN Line Card LEDs

Table 4-6 Cisco uBR10-SRP-OC12SML DPT WAN Line Card LEDs

LED Status Description

POWER Green

Off

Indicates that power is being supplied to the

Cisco uBR10-SRP- OC12SML DPT WAN line card.

Power off.

STATUS - bi-color Yellow

Green

Indicates that the CPU is in the bootup process, self test, or

downloading code.

Indicates that the CPU has successfully completed the boot,

self test, and code download process, and that the

Cisco uBR10-SRP- OC12SML DPT WAN line card is the

active card.

MAINTENANCE Off

Yellow

Normally off. Indicates that no maintenance action is required.

Indicates a required maintenance operation and that the

Cisco uBR10-SRP- OC12SML DPT WAN line card can be

hot-swapped.

RX CARRIER–B Green

Off

Indicates that the DPT port WAN has detected valid SONET or

SDH framing on the received carrier.

No valid SONET or SDH framing.

ACTIVE Green

Off

Indicates that side B of the DPT port line is functioning.

Not active.

RX PKTS (Packets) Blinking

Green

Off

Indicates that the DPT port line has received a packet. This

LED flickers in normal operation, indicating traffic.

No traffic.

RX CARRIER–A Green

Off

Indicates that the DPT port line has detected valid SONET or

SDH framing on the received carrier.

No valid SONET or SDH framing.

ACTIVE Green

Off

Indicates that side A of the DPT port line is functioning.

Not Active

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Troubleshooting the OC-12 Dynamic Packet Transport Spatial Reuse Protocol WAN Card

RX PKTS (Packets) Blinking

Green

Off

Indicates that the DPT port line has received a packet. This

LED flickers in normal operation, indicating traffic.

No traffic

PASS-THROUGH Amber

Off

Indicates that the DPT port line is in a pass-through state.

Not active.

ENABLED Green

Off

Indicates that the DPT port line is enabled for operation;

however, the interface port might be in the shutdown state.

Not active.

Table 4-6 Cisco uBR10-SRP-OC12SML DPT WAN Line Card LEDs (continued)

LED Status Description

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Chapter 4 Troubleshooting Line Cards

Troubleshooting the Cisco uBR10012 OC-48 DPT/POS Line Card

The Cisco OC-48 DPT⁄POS interface module has a pair of OC-48c, fiber-optic standard connector (SC)

duplex ports that provide an SC connection for either the single-mode short-reach or single-mode

long-reach version. Figure 4-4 shows the faceplate on the Cisco OC-48 DPT⁄POS interface module,

and Ta ble 4-7 describes each LED.

Figure 4-4 Cisco OC-48 DPT Interface Module Faceplate

Table 4-7 Cisco OC-48 DPT LED Status and Description

LED Status Description

FAIL Yellow

Off

Line card is disabled

Line card is operational

ENABLE Green

Off

Port is enabled

Port is disabled

POS Green

Off

Operating in POS mode

Not operating in POS mode

SRP Green

Off

Operating in SRP mode

Not operating in SRP mode

CD Green

Off

Carrier detected

No carrier detected

TX Green

Off

Packets transported

No packets transported

RX Green

Off

Packets received

No packets received

82923

CISCO

10000

ENABLE

POS

SRP

FAI L

OC–48/STM–16 POS/SRP SM–LR

P/N ESR-10C48/P/SRPSMS

SYNC

WRAP

PASS

THRU

FAIL

Ejector lever

Captive screw

ENABLE

POS

SRP

SYNC

WRAP

PASS

THRU

Invisible laser radiation may

be emitted from

disconnected fibers or

connectors. Do not stare

into beams or view directly

with optical instruments.

Warning

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Chapter 4 Troubleshooting Line Cards

Troubleshooting the Cisco uBR10012 OC-48 DPT/POS Line Card

SYNC Green

Off

Card synchronized to mate card

Card not synchronized

WRAP Yellow

Off

Interface is wrapped

Interface not wrapped

PASS THRU Yellow

Off

DPT port line is in a pass-through state

DPT port line not in pass-through state

Table 4-7 Cisco OC-48 DPT LED Status and Description

LED Status Description

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Chapter 4 Troubleshooting Line Cards

Troubleshooting the Gigabit Ethernet Line Card

Figure 4-5 describes the LEDs on the Cisco uBR10-1GE Gigabit Ethernet line card faceplate to help you

verify correct operation.

Tip Make sure that the gigabit Ethernet Interface Converter (GBIC) type on the Cisco uBR10012 router

matches the GBIC type at the other end of the fiber optic cable.

Figure 4-5 Gigabit Ethernet Line Card Faceplate and LED Descriptions

29992

LED Status Description

Fail

Rx (receive)

Tx (transmit)

Link

Yellow

Off

Green

A major failure has disabled the

line card.

The line card is operating

properly.

Receiving traffic.

Carrier detected; the port is

able to pass traffic.

No carrier detected; the port is

not able to pass traffic.

Off

Yellow

Not receiving traffic.

Green Transmitting traffic.

Not transmitting traffic.

Green

CISCO

10000

LINK

FAIL

GIGABIT ETHERNET

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Chapter 4 Troubleshooting Line Cards

Troubleshooting the Gigabit Ethernet Line Card

Table 4-8 describes the gigabit Ethernet line card fault indications and suggests responses to each.

Table 4-8 Gigabit Ethernet Line Card Faults and Recommended Responses

Fault Type Response

Fail LED is lit yellow indicating that a major fault

has disabled the card

1. Reinsert the line card.

2. Insert the line card into another slot.

3. Replace the line card.

4. If neither of the above responses to a card

failure succeeds, call the Cisco TAC.

Fail LED blinks then lights steadily repeatedly

Card seems to be passing traffic (Tx/Rx lights),

but cannot communicate with the PRE

1. Check for bent pins on the backplane.

2. If there are no bent pins, replace with a new

line card.

Try inserting the line card in a different slot.

If the card works in a different slot, the

Cisco uBR10012 backplane may be defective.

Call the Cisco TAC.

Fail LED blinks steadily This is a user correctable problem. The steadily

blinking LED indicates a transmit failure.

To correct the problem:

1. Reinsert the GBIC.

If reinsertion fails:

2. Replace the GBIC.

Link LED does not light but the port is enabled 1. Make sure the fiber optic cable is plugged in

properly, unbroken, and undamaged.

2. Make sure that you are using the correct type

of fiber optic cable.

3. If you have autonegotiation enabled on the

local gigabit Ethernet interface, make sure

that it is enabled on the remote interface also.

If autonegotiation is disabled, it must be

disabled at the remote interface as well.

4. Replace the GBIC.

Gigabit Ethernet card resets itself intermittently. 1. Issue the show diag command. If this

indicates a “parity error” occurred, contact

Cisco TAC for possible replacement of the

card.

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Chapter 4 Troubleshooting Line Cards

Troubleshooting the Gigabit Ethernet Line Card

CHAPTER

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Replacing or Recovering Passwords

This section describes how to recover a lost enable or console login password, and how to replace a lost

enable secret password on the Cisco uBR10012 router.

Note It is possible to recover the enable or console login password. The enable secret password is encrypted,

however, and must be replaced with a new enable secret password.

Password Recovery Procedure Overview

The following is an overview of the steps in the password recovery procedure.

•If you can log in to the router, enter the show version command to determine the existing

configuration register value.

•Press the Break key to go to the bootstrap program prompt (ROM monitor). You might need to

reload the system image by power-cycling the router.

•Change the configuration register to 0x2142 so that the router ignores the startup configuration file

during bootup. This allows you to log in without using a password and to display the startup

configuration password.

•Power cycle the router by typing reload at the rommon> prompt.

•Log in to the router and enter the privileged EXEC mode.

•Enter the show startup-config command to display the passwords.

•Recover or replace the displayed passwords.

•Change the configuration register back to its original setting.

Note To recover a lost password if the break function is disabled on the router, you must have physical access

to the router.

Password Recovery Procedure

To recover or replace a lost enable, enable secret, or console login password, use this procedure:

Step 1 Attach an ASCII terminal to the console port on the router.

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Chapter 5 Replacing or Recovering Passwords

Password Recovery Procedure

Step 2 Configure the terminal to operate at 9600 baud, 8 data bits, no parity, and 1 stop bit.

Step 3 If you can log in to the router as a nonprivileged user, enter the show version command to display the

existing configuration register value, then go to Step 6. If you cannot log in to the router at all, go to the

next step.

Step 4 Press the Break key or send a break signal from the console terminal.

•If break is enabled, the router enters the ROM monitor, indicated by the ROM monitor prompt

(rommon>). Go to Step 6.

•If break is disabled, power cycle the router (turn off the router or unplug the power cord, and then

restore power). Then go to Step 5.

Step 5 Within 60 seconds of restoring the power to the router, press the break key or send a break signal. This

action causes the router to enter the ROM monitor and display the ROM monitor prompt (rommon>).

Step 6 Set the configuration register using the configuration register utility. Enter the confreg command at the

ROM monitor prompt as follows:

rommon> confreg

Answer yes to the enable “ignore system config info?” Press the return key at all other prompts to accept

the existing value.

Step 7 Reboot the router by entering the reset command:

rommon> reset

The router initializes, the configuration register is set to 0x142, and the router boots the system image

from Flash memory and enters the system configuration dialog (setup):

--- System Configuration Dialog --

Step 8 Enter no in response to the system configuration dialog prompts until the following message appears:

Press RETURN to get started!

Step 9 Press Return. The user EXEC prompt appears:

Router>

Step 10 Enter the enable command to enter privileged EXEC mode. Then enter the show startup-config

command to display the passwords in the configuration file as follows:

Router# show startup-config

Step 11 Scan the configuration file display, looking for the passwords (the enable passwords are usually located

near the beginning of the file, and the console login or user EXEC password is near the end). The

passwords displayed appear similar to the following:

enable secret 5 $1$ORPP$s9syZt4uKn3SnpuLDrhuei

enable password 23skiddoo

line con 0

password onramp

The enable secret password is encrypted and cannot be recovered; it must be replaced. Go to the next

step to replace an enable secret, console login, or enable password. If there is no enable secret password,

note the enable and console login passwords. If the enable and console login passwords are not

encrypted, go to Step 16.

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Chapter 5 Replacing or Recovering Passwords

Password Recovery Procedure

Caution Do not execute the next step unless you have determined you must change or replace the enable, enable

secret, or console login passwords. Failure to follow the steps as shown might cause you to erase the

router configuration.

Step 12 Enter the copy startup-config running-config command to load the startup configuration file into

running memory. This action allows you to modify or replace passwords in the configuration.

Router# copy startup-config running-config

Step 13 Enter the privileged EXEC command configure terminal to enter configuration mode:

Router# configure terminal

Step 14 Change all three passwords using the following commands:

Router(config)# enable secret

newpassword1

Router(config)# enable password

newpassword2

Router(config)# line con 0

Router(config-line)# password

newpassword3

Change only the passwords necessary for your configuration. You can remove individual passwords by

using the no form of the above commands. For example, entering the no enable secret command

removes the enable secret password.

Step 15 You must configure all interfaces to avoid having the system be administratively shut down:

Router(config)# interface fastethernet 0/0

Router(config-int)# no shutdown

Enter the equivalent commands for all interfaces that were originally configured. If you omit this step,

all interfaces are administratively shut down and unavailable when the router is restarted.

Step 16 Use the config-register command to set the configuration register to the original value noted in Step 3

or Step 7, or to the factory default value 0x2102.

Router(config)# config-register 0x2102

Step 17 Press Ctrl-Z (hold down the Control key while you press Z) or enter end to exit configuration mode

and return to the EXEC command interpreter.

Caution Do not execute the next step unless you have changed or replaced a password. If you skipped Step 12

through Step 15, go to Step 19. Failure to observe this caution causes you to erase the router

configuration file.

Step 18 Enter the copy running-config startup-config command to save the new configuration to NVRAM.

Step 19 Enter the reload command to reboot the router.

Step 20 Log in to the router using the new or recovered passwords.

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Chapter 5 Replacing or Recovering Passwords

Password Recovery Procedure

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APPENDIX

Unsupported Commands

The following are lists of the commands that are present but not supported for the

Cisco uBR10012 router in various releases of the Cisco IOS software.

•Unsupported Frame Relay Commands, page A-1

•HCCP Commands, page A-2

•MLPPP Commands, page A-2

•Unsupported MPLS VPN Commands, page A-3

•Unsupported PPP Commands, page A-3

•Spectrum Management Commands, page A-3

•Unsupported Telco-Return Commands, page A-3

Warning

Cisco strongly advises against using unsupported Cisco IOS commands, even if described, because such

commands can have undesirable effects upon the performance of the Cisco CMTS. In particular, Cisco advises

against using any unsupported commands that pertain to service-policy or to Modular Quality of Service

command-line interface (MQC) while Parallel Express Forwarding (PXF) is running on the Cisco CMTS.

Such commands may cause the Cisco CMTS to hang with unpredictable recovery times.

Unsupported Frame Relay Commands

The following commands are not supported in any Cisco IOS software release.

•FRF.12 fragmentation commands

•FRF.11 VoFR commands

•frame-relay adaptive-shaping {becn | foresight}

•frame-relay bc {in | out} bits

•frame-relay be {in | out} bits

•frame-relay cir {in | out} bps

•frame-relay custom-queue-list list-number

•frame-relay de-group group-number dlci

•frame-relay ip [rtp | tcp] header-compression [passive]

•frame-relay map protocol protocol-address dlci [broadcast] [ietf | cisco] [payload-compress

{packet-by-packet | frf9 stac [hardware-options]}]

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Appendix A Unsupported Commands

HCCP Commands

•frame-relay map ip ip-address dlci [broadcast] [cisco | ietf] [nocompress] tcp

header-compression {active | passive}

•frame-relay mincir {in | out} bps

•frame-relay traffic-rate average [peak]

•frame-relay traffic-shaping

•show frame-relay ip [rtp | tcp] header-compression [interface]

HCCP Commands

The following commands are supported in Cisco IOS Release 12.2(8)BC2 and later 12.2 BC releases.

These commands are not supported in previous releases.

•hccp authenticate

•hccp authenticate key-chain

•hccp ds-switch

•hccp lockout

•hccp protect

•hccp revert

•hccp reverttime

•hccp switch

•hccp timers

•hccp track

•hccp unlockout

•hccp working

•show hccp

•show hccp interface

•debug hccp authentication

•debug hccp events

•debug hccp sync

MLPPP Commands

The following commands are supported in Cisco IOS Release 12.2(4)BC1 and later 12.2 BC releases.

These commands are not supported in previous releases.

•multilink load-threshold

•multilink max-fragments

•ppp multilink fragment-delay

•ppp multilink fragmentation

•ppp multilink idle-link

•ppp multilink interleave

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Appendix A Unsupported Commands

Unsupported MPLS VPN Commands

The following commands are not supported in any Cisco IOS software release.

•ip vrf

•ip vrf forwarding

•mpls ip

•mpls label-protocol ldp

•show ip protocols vrf

•show ip vrf

•show ip route vrf

Unsupported PPP Commands

The following commands are not supported in any Cisco IOS software release.

•compress [predictor | stac | mppc [ignore-pfc]]

•debug ppp cbcp

•ppp bridge appletalk

•ppp bridge ip

•ppp bridge ipx [novell-ether | arpa | sap | snap]

•ppp reliable-link

Spectrum Management Commands

The following commands are supported in Cisco IOS Release 12.2(8)BC2 and later 12.2 BC releases.

These commands are not supported in previous releases.

•cable upstream hop-priority

•cable upstream threshold

•show cable modem [ip-address | interface | mac-address] snr

•show controllers cable upstream spectrum

Unsupported Telco-Return Commands

The following commands are not supported in any Cisco IOS software release.

•cable telco-return enable

•cable telco-return interval

•cable telco-return spd dhcp-authenticate

•cable telco-return spd dhcp-server

•cable telco-return spd dial-timer

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Appendix A Unsupported Commands

Unsupported Telco-Return Commands

•cable telco-return spd factory-default

•cable telco-return spd manual-dial

•cable telco-return spd password

•cable telco-return spd phonenum

•cable telco-return spd ppp-authenticate

•cable telco-return spd radius-realm

•cable telco-return spd service-provider

•cable telco-return spd threshold

•cable telco-return spd username

•debug cable telco-return

•debug telco-return msg

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APPENDIX

Recommended Tools and Test Equipment

Table B-1 lists the basic tools and test equipment necessary to perform general maintenance and

troubleshooting tasks on the Cisco uBR10012 router.

The following sections describe advanced testing equipment to aid in complex problem isolation.

Testing with Digital Multimeters and Cable Testers

Use a digital multimeter to measure parameters such as AC and DC voltage, current, resistance,

capacitance, cable continuity. Use cable testers, also, to verify physical connectivity.

Use cable testers (scanners) to check physical connectivity. Cable testers are available for shielded

twisted pair (STP), unshielded twisted pair (UTP), 10BaseT, and coaxial and twinax cables. A given

cable tester might be able to perform any of the following functions:

•Test and report on cable conditions, including near-end crosstalk (NEXT), attenuation, and noise.

•Perform time domain reflectometer (TDR), traffic monitoring, and wire map functions.

•Display Media Access Control (MAC) layer information about LAN traffic, provide statistics such

as network utilization and packet error rates, and perform limited protocol testing (for example,

TCP/IP tests such as ping).

Table B-1 Recommended Tools and Test Equipment

Equipment Description

Number 2 Phillips and flat-head

screwdrivers

Small and medium-sized.

Voltage tester Refer to the “Testing with Digital Multimeters and Cable

Testers” section on page B-1.

Optical fiber test equipment Refer to the “Testing with Digital Multimeters and Cable

Testers” section on page B-1.

Cable testing equipment Refer to the “Testing with Digital Multimeters and Cable

Testers” section on page B-1.

ESD-preventive wrist or ankle

strap with connection cord

—

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Appendix B Recommended Tools and Test Equipment

Testing with TDRs and OTDRs

Test fiber-optic cable both before installation (on-the-reel testing) and after installation. Continuity

testing of the fiber requires either a visible light source or a reflectometer. Light sources capable of

providing light at the three predominant wavelengths, 850 nanometers (nm), 1300 nm, and 1550 nm, are

used with power meters that can measure the same wavelengths and test attenuation and return loss in

the fiber.

Testing with TDRs and OTDRs

This section describes time domain reflectometers (TDRs) and optical time domain reflectometers

(OTDRs), which are typically used to detect cable defects.

Testing with TDRs

Use time domain reflectometers to test for the following cable defects:

•Open and short circuits

•Crimps, kinks, and sharp bends

•Impedance mismatches

•Other defects

A TDR works by “bouncing” a signal off the end of the cable. Open circuits, short circuits and other

problems reflect the signal back at different amplitudes, depending on the problem.

A TDR measures:

•the amount of time it takes for the signal to reflect

•The physical distance to a fault in the cable

•The length of a cable

Some TDRs can also calculate the propagation rate based on a configured cable length.

Testing with OTDRs

Use optical time domain reflectometers to:

•Locate fiber breaks

•Measure attenuation

•Measure the length of a fiber

•Measure splice or connector losses

An OTDR can be used to identify the “signature” of a particular installation, noting attenuation and

splice losses. This baseline measurement can then be compared with future signatures if you suspect a

problem in the system.

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Appendix B Recommended Tools and Test Equipment

Testing with Breakout Boxes, Fox Boxes, and BERTs/BLERTs

Use breakout boxes, fox boxes, and bit/block error rate testers (BERTs/BLERTs) to measure the digital

signals present at:

•PCs

•Printers

•Modems

•CSU/DSUs

These devices can monitor data line conditions, analyze and trap data, and diagnose problems common

to data communication systems. Traffic from data terminal equipment (DTE) through data

communications equipment (DCE) can be examined to:

•Isolate problems

•Identify bit patterns

•Ensure that the correct cabling is installed

These devices cannot test media signals such as Ethernet, Token Ring, or FDDI.

Testing with Network Monitors

Use network monitors to:

•Track packets crossing a network

•Provide an accurate picture of network activity at any moment

•Provide a historical record of network activity over a period of time

Network monitors do not decode the contents of frames. Monitors are useful for baselining, in which the

activity on a network is sampled over a period of time to establish a normal performance profile, or

baseline.

Monitors collect information such as packet sizes, the number of packets, error packets, overall usage of

a connection, the number of hosts and their MAC addresses, and details about communications between

hosts and other devices. This data can be used to:

•Create profiles of LAN traffic

•Locate traffic overloads

•Plan for network expansion

•Detect intruders

•Establish baseline performance

•Distribute traffic more efficiently

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Appendix B Recommended Tools and Test Equipment

Testing with Network Analyzers

Use network analyzers (also called protocol analyzers) to decode protocol layers in a recorded frame and

present the layers as readable abbreviations or summaries, detailing which layer is involved (physical,

data link, and so forth) and the function each byte or byte content serves.

Most network analyzers can perform many of the following functions:

•Filter traffic that meets certain criteria so that, for example, all traffic to and from a particular device

can be captured.

•Time-stamp captured data.

•Present protocol layers in an easily readable form.

•Generate frames and transmit them onto the network.

•Incorporate an “expert” system in which the analyzer uses a set of rules, combined with information

about the network configuration and operation, to diagnose and solve, or offer potential solutions

to, network problems.

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INDEX

access-list compiled command 3-13

access lists 3-13

AC PEM faults 2-1 to 2-3

ACTIVE LED

OC-12 DPT/SRP 4-14

TCC+ 4-9

alignment errors 3-15

correctable 3-15

fatal 3-16

alphanumeric display

list of messages 3-2

messages 1-6

ARP traffic problems 3-9

BERT B-3

bit error rate testers B-3

BLERT B-3

block error rate testers B-3

blower failures 2-7

UNIVERSAL BROADBAND ROUTER UBR10012 Troubgd

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