3Com 2250 Owners Manual 3Com® Baseline Switch Plus (3C16476BS)

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Baseline Switch 2250 Plus
(3C16476BS) User Guide

http://www.3com.com/
Part No. DUA16476B-SAA02
Published April 2005

3Com Corporation • 350 Campus Drive • Marlborough • MA USA 01752-3064
Copyright © 2004, 2005, 3Com Corporation. All rights reserved. No part
of this documentation may be reproduced in any form or by any means or
used to make any derivative work (such as translation, transformation, or
adaptation) without written permission from 3Com Corporation.
3Com Corporation reserves the right to revise this documentation and to
make changes in content from time to time without obligation on the part
of 3Com Corporation to provide notification of such revision or change.
3Com Corporation provides this documentation without warranty, term, or
condition of any kind, either implied or expressed, including, but not
limited to, the implied warranties, terms or conditions of merchantability,
satisfactory quality, and fitness for a particular purpose. 3Com may make
improvements or changes in the product(s) and/or the program(s) described
in this documentation at any time.
If there is any software on removable media described in this
documentation, it is furnished under a license agreement included with the
product as a separate document, in the hard copy documentation, or on
the removable media in a directory file named LICENSE.TXT or
!LICENSE.TXT. If you are unable to locate a copy, please contact 3Com and
a copy will be provided to you.
UNITED STATES GOVERNMENT LEGEND
If you are a United States government agency, then this documentation
and the software described herein are provided to you subject to the
following:
All technical data and computer software are commercial in nature and
developed solely at private expense. Software is delivered as “Commercial
Computer Software” as defined in DFARS 252.227-7014 (June 1995) or as
a “commercial item” as defined in FAR 2.101(a) and as such is provided
with only such rights as are provided in 3Com’s standard commercial
license for the Software. Technical data is provided with limited rights only
as provided in DFAR 252.227-7015 (Nov 1995) or FAR 52.227-14 (June
1987), whichever is applicable. You agree not to remove or deface any
portion of any legend provided on any licensed program or documentation
contained in, or delivered to you in conjunction with, this User Guide.
Unless otherwise indicated, 3Com registered trademarks are registered in
the United States and may or may not be registered in other countries.
3Com and the 3Com logo are registered trademarks of 3Com Corporation.

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All other company and product names may be trademarks of the respective
companies with which they are associated.
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It is the policy of 3Com Corporation to be environmentally-friendly in all
operations. To uphold our policy, we are committed to:
Establishing environmental performance standards that comply with
national legislation and regulations.
Conserving energy, materials and natural resources in all operations.
Reducing the waste generated by all operations. Ensuring that all waste
conforms to recognized environmental standards. Maximizing the
recyclable and reusable content of all products.
Ensuring that all products can be recycled, reused and disposed of safely.
Ensuring that all products are labelled according to recognized
environmental standards.
Improving our environmental record on a continual basis.
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3Com processes allow for the recovery, reclamation and safe disposal of all
end-of-life electronic components.
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3Com products do not contain any hazardous or ozone-depleting material.
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CONTENTS

Supplying Power to the Switch 16
Checking for Correct Operation 16
Connecting a Network Device 17
Using SFP Transceivers 18
Approved SFP Transceivers 18
Inserting an SFP Transceiver 18
Removing an SFP Transceiver 19
Performing Spot Checks 19

ABOUT THIS GUIDE
Conventions 5
Related Documentation 6
Documentation Comments 6

INTRODUCING THE BASELINE SWITCH
Overview of the Baseline Switch 2250 Plus 7
Features and Capabilities 7
Autosensing of MDI/MDIX Connections 7
Autonegotiating 10/100 Mbps Ports 7
SFP Ports 8
Traffic Prioritization 8
Forwarding of BPDU Packets 8
Physical Features 9
Front Panel 9
Rear Panel 12
Package Contents 12

Requirements for Accessing the Web Interface 21
Running the Discovery Application 21
Logging On to the Web Interface 22
Navigating the Web Interface 23
Menu 23
Buttons 24
Port Status 24
Accessing the Interface Without Using Discovery 24
DHCP Assigned IP Address 25
Manually Assigned (Static) IP Address 25

INSTALLING THE SWITCH
Before You Begin 13
Positioning the Switch 13
Aufstellen des Switch 14
Rack-Mounting or Free-Standing 14
Using the Mounting Kit 14
Montagesatz Anweisungen 15
Placing Units On Top of Each Other

CONNECTING TO THE WEB INTERFACE

CONFIGURING THE SWITCH
Configuration Overview 27
Viewing Summary Information 27
Changing the Admin Password 28
Modifying the IP Address Settings 29
Automatic IP Configuration 29

Setting the IP Address 30
Configuring Port Settings 31
Basic Port Configuration 31
Advanced Port Configuration 32
Default Port Settings 32
Configuring VLANs 32
Creating a VLAN 33
Deleting VLANs 33
Modifying VLANs 34
Defining VLAN Membership 34
Sample VLAN Configurations 34
Configuring Trunking 36
Guidelines for Creating Trunks 36
Creating, Modifying, and Deleting Trunks 37
Defining Trunk Membership 37
Viewing Trunk Information 37
Monitoring Traffic 38
Using the System Tools 39
Restarting the Switch 39
Resetting and Backing Up/Restoring Configuration
Upgrading the System Software 40
Configuring the Spanning Tree 41
802.1p Prioritization 41

OBTAINING SUPPORT FOR YOUR PRODUCT
Register Your Product 47
Purchase Value-Added Services 47
Troubleshoot Online 47
Access Software Downloads 47
Telephone Technical Support and Repair
Contact Us 48

SAFETY INFORMATION
Important Safety Information 51
France and Peru Only 51
Power Cord Set 52
Consignes Importantes de Sécurité 52
France et Pérou Uniquement 53
Cordon électrique 53
Wichtige Sicherheitshinweise Informationen
Stromkabel 54

TECHNICAL INFORMATION
Related Standards
Environmental
Physical 57
Electrical 57

57
57

TROUBLESHOOTING
Resetting to Factory Defaults 43
Forgotten Password 43
Forgotten Static IP Address 44
Solving LED Issues 44
If the Problem Persists 45

GLOSSARY
INDEX
REGULATORY NOTICES

ABOUT THIS GUIDE

This guide is intended for use by network administators who are responsible for installing and setting up
network equipment. Consequently, it assumes a basic
working knowledge of LANs (local area networks).
Diese Anleitung ist für die Benutzung durch
Netzwerkadministratoren vorgesehen, die für die
Installation und das einstellen von Netzwerkkomponenten verantwortlich sind; sie setzt Erfahrung bei.

If release notes are shipped with your product and
the information there differs from the information in
this guide, follow the instructions in the release notes.
Most user guides and release notes are available in
Adobe Acrobat Reader Portable Document Format
(PDF) on the 3Com World Wide Web site:
http://www.3com.com

Conventions
Table 1 and Table 2 list conventions that are used
throughout this guide.

Table 1 Notice Icons
Icon

Notice Type

Description

Information
note

Information that describes important features
or instructions

Caution

Information that alerts you to potential loss of
data or potential damage to an application,
system, or device

Warning

Information that alerts you to potential
personal injury

Table 2 Text Conventions
Convention

Description

Screen displays

This typeface represents information as it
appears on the screen.

The words “enter”
and “type”

When you see the word “enter” in this guide,
you must type something, and then press
Return or Enter. Do not press Return or Enter
when an instruction simply says “type.”

Words in italics

Italics are used to:
■

Emphasize a point.

■

Denote a new term at the place where it is
defined in the text.

■

Identify menu names, menu commands, and
software button names. Examples:
From the Help menu, select Contents.
Click OK.

ABOUT THIS GUIDE

Related Documentation
In addition to this guide, each 3Com Baseline Switch
2250 Plus documentation set includes the following:
■

Online Help – Accessible from the Web interface,
provides information that helps you perform tasks
using the Web interface.

■

Release Notes – Provide information about the current software release, including new features,
modifications, and known problems.

Documentation Comments
Your suggestions are very important to us. They will
help make our documentation more useful to you.
Please e-mail comments about this document to
3Com at:
pddtechpubs_comments@3com.com

Please include the following information when contacting us:
■

Document title

■

Document part number (on the title page)

■

Page number (if appropriate)

Example:
■

3Com Baseline Switch 2250 Plus User Guide

■

Part number: DUA16476B-SAA01

■

Page 25

Please note that we can only respond to comments
and questions about 3Com product documentation
at this e-mail address. Questions related to technical
support or sales should be directed in the first
instance to your network supplier.

INTRODUCING THE BASELINE SWITCH

This chapter provides an overview of the features and
capabilities of the 3Com® Baseline Switch 2250 Plus.
It also identifies the contents of the Switch package
and helps you get to know the physical features of
the device.

Overview of the Baseline Switch 2250 Plus
The 3Com® Baseline Switch 2250 Plus is a versatile,
easy-to-use unmanaged switch. It is ideal for users
who want the high-speed performance of 10/100
switching with the added functionality of Gigabit
links but do not need sophisticated management
capabilities.
The Switch is shipped ready for use. No configuration
is necessary, unless you want to configure advanced
features such as VLAN support and link aggregation.

Features and Capabilities
The Switch has 48 shielded RJ-45, 10/100 Mbps
auto-negotiating ports and two 10/100/1000BASE-T
ports that operate in conjunction with two Small
Form Factor Pluggable (SFP) transceiver slots on the
front panel. Use these SFP transceiver slots for easy,
flexible connection to fiber-based Gigabit media.

While there are four physical Gigabit ports, only a
maximum of two can be operational at any given
time.

Autosensing of MDI/MDIX Connections
All ports on the Switch can autosense both medium
dependent interface (MDI) and medium dependent
interface crossover (MDIX) connections. This allows
you to connect network devices to each port using
either a normal straight-through TP (twisted pair)
cable or a ‘crossover’ TP cable.
Any port can therefore be used to connect to another
switch port, server, or workstation without additional
configuration.

Autonegotiating 10/100 Mbps Ports
Each 10/100 Mbps port automatically determines the
speed and duplex mode of the connected equipment
and provides a suitable switched connection. The
1000BASE-T ports also support automatic
10/100/1000 Mbps speed detection.
The 10/100 Mbps connections on these 1000BASE-T
ports operate in full-duplex mode.

CHAPTER 1: INTRODUCING THE BASELINE SWITCH

SFP Ports
The two SFP ports support fiber Gigabit Ethernet
short-wave (SX) and long-wave (LX) SFP transceivers
in any combination. This offers you the flexibility of
using SFP transceivers to provide connectivity
between the Switch and a 1000 Mbps core network.
When an SFP port is in operation, the corresponding
10/100/1000BASE-T port is disabled.

Traffic Prioritization
The Switch offers priority queuing, which means all
packets that are received are examined to see if they
have been priority encoded. If a packet has been priority encoded, then the Switch will read the priority
level and determine whether the packet should be
directed through the normal or high priority channel.
This feature is useful during excessive loads when one
type of traffic may require priority over another. The
Switch is configured to comply with 802.1p, VLAN
tagged frames.
Traffic prioritization ensures that high priority data is
forwarded through the Switch without being delayed
by lower priority data. It differentiates traffic into
classes and prioritizes those classes automatically.
Traffic prioritization uses the multiple traffic queues
that are present in the hardware of the Switch to
ensure that high priority traffic is forwarded on a different queue from lower priority traffic, and is given
preference over that traffic. This ensures that
time-sensitive traffic gets the highest level of service.
The 802.1D standard specifies eight distinct levels of
priority (0 to 7), each of which relates to a particular

type of traffic. The priority levels and their traffic types
are shown in the following table.
Table 3 Priority Levels for Traffic Types
Priority Level
Traffic Type
0

Best effort

Background

Standard (spare)

Excellent effort (business critical)

Controlled load (streaming multimedia)

Video (interactive media), less than 100
milliseconds latency and jitter

Voice (interactive voice), less than 10 milliseconds latency and jitter.

Network control reserved traffic

Forwarding of BPDU Packets
Within an extended local area network that implements a spanning tree protocol topology, switches
communicate with each other using bridge protocol
data unit (BPDU) packets.
If your network is implementing a spanning tree
topology across multiples switches, you can configure
3Com Baseline Switch 2250 Plus to forward or to
block and discard bridge protocol data unit (BPDU)
packets to another switch. Switches that support the
spanning tree protocol communicate with each other
using BPDU packets.
The spanning tree protocol (STP) is a mechanism that
prevents looping and broadcast storms. A spanning
tree uses the spanning tree algorithm to detect avail-

Physical Features

able communication paths between switches and to
determine the best available path and block less optimal paths.
For information on configuring BPDU forwarding and
blocking, refer to “Configuring the Spanning Tree”
on page 41.

Physical Features
Figure 1 shows the front and rear panels of the
Switch. The numbers in this diagram refer to numbered sections in “Front Panel” on page 9 and “Rear
Panel” on page 12.
Figure 1 Front and Rear Panels

4 5

2 3

Front Panel
The front panel of the Switch contains a series of indicator lights (LEDs) that help describe the state of various networking and connection operations.

(1) 48 RJ-45 Ports
WARNING: RJ-45 Ports. These are shielded RJ-45
data sockets. They cannot be used as standard traditional telephone sockets, or to connect the unit to a
traditional PBX or public telephone network. Only
connect RJ-45 data connectors, network telephony
systems, or network telephones to these sockets.
Either shielded or unshielded data cables with
shielded or unshielded jacks can be connected to
these data sockets.
AVERTISSEMENT: Points d’accès RJ-45. Ceux-ci sont
protégés par des prises de données. Ils ne peuvent
pas être utilisés comme prises de téléphone conventionnelles standard, ni pour la connection de l’unité à
un réseau téléphonique central privé ou public. Raccorder seulement connecteurs de données RJ-45,
systèmes de réseaux de téléphonie ou téléphones de
réseaux à ces prises.
Il est possible de raccorder des câbles protégés ou
non protégés avec des jacks protégés ou non protégés à ces prises de données.
WARNHINWEIS: RJ-45-Porte. Diese Porte sind
geschützte Datensteckdosen. Sie dürfen weder wie
normale traditionelle Telefonsteckdosen noch für die
Verbindung der Einheit mit einem traditionellem privatem oder öffentlichem Telefonnetzwerk gebraucht
werden. Nur RJ-45-Datenanscluße, Telefonnetzsysteme or Netztelefone an diese Steckdosen
anschließen.

CHAPTER 1: INTRODUCING THE BASELINE SWITCH

Entweder geschützte oder ungeschützte Buchsen
dürfen an diese Datensteckdosen angeschlossen werden.
The Switch has 48 10/100 Mbps autonegotiating
ports (ports 1 to 48). Their speed and duplex mode
(half-duplex or full-duplex) are automatically determined by the capabilities of the connected device.
Each port also supports automatic MDI/MDI-X detection and can be connected to either a 10BASE-T, or a
100BASE-TX device.
CAUTION: The Switch supports full-duplex autonegotiation. If the connected device does not support
autonegotiation, the Switch will operate in
half-duplex mode (even if the attached device is operating in full-duplex mode).

connections to workstations or servers, or to other
switches or hubs.
The two SFP ports support fiber Gigabit Ethernet
short-wave (SX) and long-wave (LX) SFP transceivers
in any combination. This offers you the flexibility of
using SFP transceivers to provide connectivity
between the Switch and remote 1000 Mbps workgroups or to create a high-capacity aggregated link
backbone connection.
SFP ports are numbered 49 and 50 on the Switch.
When an SFP port is active, it has priority over the
10/100/1000 port of the same number. The corresponding 10/100/1000 port is disabled when an SFP
transceiver is plugged in.
(3) Link/Activity LEDs

In such a configuration, you may notice some
degradation of network performance. 3Com
recommends that you use devices that are capable of
autonegotiation (and that you ensure that
autonegotiation is enabled, if it is a configurable
option). (see “Troubleshooting” on page 43).
(2) 10/100/1000BASE-T/SFP Ports
Ports 49 and 50 are combination Gigabit RJ-45 ports
with shared Small Form Factor Pluggable (SFP) transceiver slots. If an SFP transceiver (purchased separately) is installed in a slot and is active, the associated
RJ-45 port of the same number is disabled.
The 1000BASE-T RJ-45 ports support automatic
MDI/MDI-X operation, so you can use
straight-through or crossover cables for all network

The following tables describe the LEDs visible on the
front of the Switch, and how to read their status
according to color.
Table 4 10BASE-T/100BASE-TX Ports
Status
Meaning
Green

Link established, operating at 100 Mbps

Yellow

Link established, operating at 10 Mbps

Physical Features

Status

Meaning

Status

Meaning

Flashing

Packets are being received or transmitted on the port

Flashing Yellow to
Green

Port disabled or link loopback error

Off

Link not established, either nothing is
connected to the port, or there is a
problem.

Off

Link not established, either nothing is
connected to the port, or there is a
problem.

■

Verify that the attached device is
powered on

■

Verify that the attached device is
powered on

■

Verify that the cable or fiber is the
correct type and is not faulty

■

Verify that the cable or fiber is the
correct type and is not faulty

■

For fiber connections, ensure that the
receive (RX) and transmit (TX) cable
connectors are not swapped

■

For fiber connections, ensure that the
receive (RX) and transmit (TX) cable
connectors are not swapped

If these checks do not identify the cause
of the problem, it may be that the unit
or the device connected to the port is
faulty. Contact your 3Com network supplier for further advice.
Table 5 10BASE-T/100BASE-TX/1000BASE-T Ports
Status
Meaning
Green

Link established, operating at 1000
Mbps

Yellow

Link established, operating at 10 or 100
Mbps

Flashing Green

Packets are being received or transmitted on the port at 1000 Mbps

Flashing Yellow

Packets are being received or transmitted on the port at 10 or 100 Mbps

If these checks do not identify the cause
of the problem, it may be that the unit
or the device connected to the port is
faulty. Contact your 3Com network supplier for further advice.

(4) Module Active LEDs
The Module Active LEDs show the status of any SFP
modules that are installed.
Status

Meaning

Green

Fiber SFP is inserted in the slot

Off

No fiber SFP is inserted in the slot

(5) Power LED
The Power LED shows the power status of the Switch.
Status

Meaning

Green

The unit is powered on and ready for use

CHAPTER 1: INTRODUCING THE BASELINE SWITCH

Off

The unit is not receiving power:
■

Verify that the power cord is connected correctly

■

If the unit still does not operate, contact your
3Com network supplier

Flashing
Green

■

Power-on self-test is in progress

Yellow

■

Power-on self-test or loopback test failed. If
this occurs, reset the Switch to factory
defaults. Refer to “Resetting to Factory

Defaults”

(6) Self-Adhesive Pads
The unit is supplied with four self-adhesive rubber
pads.
Do not apply the pads if you intend to rack-mount
the unit.
If the unit is to be part of a free-standing stack, apply
the pads to each marked corner area on the underside of the unit. Place the unit on top of the lower
unit, ensuring that the pads locate with the recesses
of the lower unit.

Rear Panel
(7) Power Supply
The Switch automatically adjusts to the supply voltage. Only use the power cord that is supplied with
the unit.

(8) Recovery Button
Use the Recovery button on the rear panel to reset
the Switch to its factory defaults. For more information, refer to “Resetting to Factory Defaults” on
page 43.

Package Contents
The 3Com Baseline Switch 2250 Plus package
includes the following items:
■

One 3Com Baseline Switch 2250 Plus unit

■

One power cord

■

Four standard height, self-adhesive rubber pads

■

One mounting kit

■

One CD-ROM, which contains this User Guide and
the 3Com Discovery application

■

One warranty flyer

Before installing and using the Switch, verify that your
Switch package has all these items. If any of the
above items are damaged or missing, contact your
3Com network supplier immediately.

INSTALLING THE SWITCH

This chapter contains information that you need to
install and set up the Switch. It covers the following
topics:
■

Positioning the Switch

■

Rack-Mounting or Free-Standing

■

Supplying Power to the Switch

■

Connecting a Network Device

■

Connecting a Network Device

■

Performing Spot Checks

Before You Begin
WARNING: Safety Information. Before installing or
removing any components from the Switch or carrying out any maintenance procedures, read the safety
information provided in Appendix B of this guide.
AVERTISSEMENT: Consignes de sécurité. Avant
d'installer ou d'enlever tout composant du Switch ou
d'entamer une procédure de maintenance, lisez les
informations relatives à la sécurité qui se trouvent
dans Appendix B (l'Appendice B) de ce guide.
WARNHINWEIS: Sicherheitsinformationen. Bevor
Sie Komponenten aus dem Switch entfernen oder
dem Switch hinzufuegen oder Instandhaltungsarbe-

iten verrichten, lesen Sie die Sicherheitsanweisungen,
die in Appendix B (Anhang B) in diesem Handbuch
aufgefuehrt sind.

Positioning the Switch
The Switch is suitable for use in an office environment
where it can be free-standing or mounted in a standard 19-inch equipment rack.
Alternatively, the Switch can be rack-mounted in a
wiring closet or equipment room. A mounting kit,
containing two mounting brackets and four screws, is
supplied with the Switch.
When deciding where to position the Switch, ensure
that:
■

It is accessible and cables can be connected easily.

■

Cabling is away from sources of electrical noise.
These include lift shafts, microwave ovens, and air
conditioning units. Electromagnetic fields can
interfere with the signals on copper cabling and
introduce errors, therefore slowing down your network.

■

Water or moisture cannot enter the case of the
unit.

■

Air flow around the unit and through the vents in
the side of the case is not restricted (3Com recom-

CHAPTER 2: INSTALLING THE SWITCH

mends that you provide a minimum of 25 mm or 1
in. clearance).

3Com empfiehlt das Sie 25mm (1 Inch) Zwischenraum sicherstellen.

■

The air is as free of dust as possible.

■

Die Luft so frei wie möglich von Staub ist.

■

Temperature operating limits are not likely to be
exceeded. It is recommended that the unit is
installed in a clean, air conditioned environment.

■

Es unwahrscheinlich ist das die Betriebstemperatur
überschritten wird. 3Com empfiehlt das Sie den
Switch in einer sauberen, klimatisierten Umgebung
installieren.

It is always good practice to wear an anti-static wrist
strap when installing network equipment, connected
to a ground point. If one is not available, try to keep
in contact with a grounded rack and avoid touching
the unit's ports and connectors, if possible. Static discharge can cause reliability problems in your equipment.

Aufstellen des Switch
Bei der Entscheidung wo Sie den Switch positionieren, stellen Sie sicher das:
■

Der Switch zugänglich ist und die Kabel leicht
angeschlossen werden können.

■

Die Kabel nicht in der nähe von elektrischen
Störquellen befinden. Das schließt Aufzugsschächte, Mikrowellen und Klimaanlagen ein. Elektromagnetische Felder können die Signale in den
Kupferleitungen stören, und Fehler verursachen,
was die Verlangsamung Ihres Netzwerkes zur
Folge haben kann.

■

Weder Wasser noch Feuchtigkeit in das Gehäuse
eindringen kann.

■

Die Luftzirkulation um den Switch und durch die
Öffnungen des Gehäuses nicht behindert wird.

Rack-Mounting or Free-Standing
The unit can be mounted in a 19-inch equipment rack
using the supplied mounting kit, (see “Using the
Mounting Kit” on page 14), or it can be free-standing. Do not place objects on top of the unit or stack.
CAUTION: If installing the Switch in a free-standing
stack of different size Baseline or SuperStack® 3 units,
the smaller units must be installed above the larger
ones. Do not have a free-standing stack of more than
six units.

Using the Mounting Kit
The Switch is supplied with two mounting brackets
and four screws. These are used for rack mounting
the unit. When mounting the unit, take note of the
guidelines given in “Positioning the Switch” on
page 13.
The Switch is 1U (1.75 in.) high and will fit in a standard 19-inch rack.
CAUTION: Before continuing, disconnect all cables
from the unit. Remove the self-adhesive pads from
the underside of unit, if already fitted.

Rack-Mounting or Free-Standing

To rack-mount the Switch:
1 Place the unit the right way up on a hard, flat surface

with the front facing towards you.
2 Locate a mounting bracket over the mounting holes

on one side of the unit.
3 Insert the two screws supplied in the mounting kit

and fully tighten with a suitable screwdriver.
Figure 2 Inserting the Screws

Montagesatz Anweisungen
Der Switch wird mit zwei Halterungen und vier
Schrauben geliefert. Diese werde für den Einbau in
einen Baugruppenträger benutzt. Bei der Montage
der Baugruppe beachten Sie die Anweisungen aus
“Aufstellen des Switch“.
Der Switch ist eine Baueinheit hoch und passt in einen
Standard 19'' (Zoll) Baugruppenträger.
ACHTUNG: Entfernen Sie alle Kabel, bevor Sie fortfahren. Entfernen Sie die selbstklebenden Polster
(Füße) von der Unterseite der Baugruppe, falls diese
bereits angebracht sind.
1 Plazieren Sie die Baugruppe aufrecht auf einer harten,

ebenen Fläche mit der Vorderseite zu Ihnen.
2 Ordnen Sie eine der Halterungen über den Löchern

an der Seite der Baugruppe an.
3 Stecken Sie zwei der mitgelieferten Schrauben in die

Löcher und drehen Sie diese mit einem geeigneten
Schraubendreher fest.
4 Widerholen Sie letzten beiden Schritte auf der

anderen Seite der Baugruppe.
4 Repeat the two previous steps for the other side of

the unit.
5 Insert the unit into the 19-inch rack and secure with

suitable screws (not provided). Ensure that the ventilation holes are not obstructed.
6 Reconnect the network cables.

5 Führen Sie die Baugruppe in den 19" (Zoll) Baugrup-

penträger ein und sichern sie die Baugruppe mit
geeigneten Schrauben. (Nicht im Lieferumfang
enthalten.)
6 Schließen Sie alle Kabel wieder an.

Placing Units On Top of Each Other
If the Switch units are free-standing, up to four units
can be placed one on top of the other. If you are

CHAPTER 2: INSTALLING THE SWITCH

mixing a variety of Baseline and SuperStack units, the
smaller units must be positioned at the top.
If you are placing Switch units one on top of the
other, you must use the self-adhesive rubber pads
supplied. Apply the pads to the underside of each
Switch, sticking one in the marked area at each corner. Place the Switch units on top of each other,
ensuring that the pads of the upper unit line up with
the recesses of the lower unit.

Supplying Power to the Switch
Power problems can be the cause of serious failures
and downtime in your network. Ensure that the
power input to your system is clean and free from
sags and surges to avoid unforeseen network outages. 3Com recommends that you install power conditioning, especially in areas prone to black outs,
power dips and electrical storms.
The unit is intended to be grounded. Ensure it is connected to earth ground during normal use. Installing
proper grounding helps to avoid damage from lightning and power surges.
Before powering on the Switch, verify that network
cables and the power cable are securely connected.
CAUTION: The Switch has no ON/OFF switch; the
only method of connecting or disconnecting main
power is by connecting or disconnecting the power
cord.

To power on the Switch:
1 Plug the power cord into the power socket on the

rear panel of the Switch. Refer to “(7) Power Supply”
on page 12 for more information.
2 Plug the other end of the power cord into a power

outlet.
When the Switch is powered on, the Power LED lights
up. If the Power LED does not light up, refer to “(5)
Power LED” on page 11 for more information.

Checking for Correct Operation
After you power on the Switch, it automatically performs a power-on self-test (POST). During POST, the
Power LED on the front panel of the Switch flashes
green.
When POST is complete, the Power LED turns green.
If the Power LED turns yellow after POST, it means
that POST failed.
Table 6 summarizes the possible colors for the Power
LED after POST.
Table 6 Possible Power LED Colors After POST
Color
State
Green

The unit is powered on and ready for use

Connecting a Network Device

Color

State

Yellow

Power-on self-test or loopback test failed.
This can happen if a ports or ports fail
when the Switch was powered on.

Off

The unit is not receiving power:
■

■

Verify that the power cord is connected
correctly, and then try powering on the
Switch again
If the Switch still does not operate, contact your 3Com network supplier

If POST fails, try the following:
■

■

Power off the Switch, and then power it on again.
Check the Power LED and see if POST was successfully completed.

Connecting a Network Device
To connect a network device to the Switch, use Category 5 unshielded or shielded (screened) 100 Ohm TP
cables (or Category 3 cables for 10 Mbps connections).
For optimal connections, ensure that the cable length
for each connection is not longer than 100 m (328 ft).
Figure 3 Connecting Devices to the Switch
Baseline 10/100 switch

Endstations on switched
100 Mbps connections

Baseline 10/100 switch

Endstations on switched
100 Mbps connections

Reset the Switch. See “Resetting to Factory
Defaults” on page 43.
1000 Mbps copper
or fiber connection
to backbone or
server/workstation

Baseline Switch 2250 Plus

CAUTION: Resetting the Switch to its factory defaults
erases all your settings. You will need to reconfigure
the Switch after you reset it.
1000 Mbps link
10 or 100 Mbps link

Endstations
on switched
10 or 100 Mbps
connection

If these do not resolve the issue:
■

■

Check the 3Com Knowledgebase for a solution. To
visit the 3Com Knowledgebase Web site, start your
Web browser, and then enter
http://knowledgebase.3com.com.
Contact your 3Com network supplier for assistance.

Server on switched
1000 Mbps
connection

To connect a device to the Switch:
1 Connect one end of the cable to an RJ-45 port on the

Switch.
2 Connect the other end to the appropriate RJ-45 port

on the connecting device.
For 1000BASE-T operation, 3Com recommends using
Category 5e or 6 cables.

CHAPTER 2: INSTALLING THE SWITCH

fiber-optic cable or to multimode fiber using a conditioned launch cable.

Using SFP Transceivers
The following sections describe how to insert and
remove an SFP transceiver from an SFP slot.

If the SFP transceiver is faulty, it will not operate
within the Switch. See “Troubleshooting” on
page 43.

SFP transceivers are hot-insertable and hot-swappable. You can remove them from and insert them into
any SFP port without having to power off the Switch.

To insert an SFP transceiver:
1 Hold the transceiver so that the fiber connector is

toward you and the product label is visible, as shown
in Figure 4. Ensure the wire release lever is closed (in
the upright position).

Approved SFP Transceivers
The following list of approved SFP transceivers is correct at the time of publication:
■

3CSFP91 SFP (SX)

■

3CSFP92 SFP (LX)

Figure 4 Inserting the SFP Transceiver

To access the latest list of approved SFP transceivers
for the Switch on the 3Com Corporation World Wide
Web site, enter this URL into your Internet browser:
http://www.3com.com

3Com recommends using 3Com SFPs on the Switch.
If you insert an SFP transceiver that is not supported,
the Switch will not recognize it.

Product
label

Wire release
lever

Inserting an SFP Transceiver
Suitable slot
on host Switch

To be recognized as valid, the SFP transceiver must be
one of the following:
■

■

1000BASE-SX SFP transceiver – Use this transceiver
to connect the Switch directly to a multimedia
fiber-optic cable.
1000BASE-LX SFP transceiver – Use this transceiver
to connect the Switch directly to a single-mode

2 Gently slide the transceiver into the SFP slot until it

clicks into place.
CAUTION: SFP transceivers are keyed and can be
properly inserted only one way. If the transceiver does

Performing Spot Checks

not click when you insert it, remove it, turn it over,
and then re-insert it.
3 Remove the plastic protective cover, if fitted.
4 Connect the fiber cable.
5 The transceiver connects to the network using a

duplex LC connector. Attach a male duplex LC connector on the network cable into the duplex LC connector on the transceiver.
6 Connect the other end of the cable to a device fitted

with an appropriate Gigabit Ethernet connection.
7 Check the Module Active LEDs on the front of the

Switch to ensure that it is operating correctly.

Removing an SFP Transceiver
Removing an SFP transceiver does not require powering off the Switch.
To remove an SFP transceiver:
1 Disconnect the cable from the transceiver.
2 Move the wire release lever downwards until it is

pointing toward you.
3 Pull the wire release lever toward you to release the

catch mechanism.
The SFP transceiver should slide out easily.

Performing Spot Checks
At frequent intervals, you should visually check the
Switch. Regular checks can give you an early warning

of a possible failure; any problems can then be
attended to when there will be least effect on users.
3Com recommends periodically checking the items
listed in Table 7.
Table 7 Items to Check
Item
Verify That
Cabling

All external cabling connections are secure
and that no cables are pulled taut

Cooling fan

Where possible, check that the cooling fan
is operating by listening to the unit. The
fan is fitted near to the front right hand
side of the unit (when viewed from the
front).

If you experience any problems operating the Switch,
refer to “Troubleshooting” starting on page 43.

CHAPTER 2: INSTALLING THE SWITCH

CONNECTING TO THE WEB INTERFACE

The Switch has a built-in Web interface that you can
use to set the admin password, change the IP address
that is assigned to the Switch, and configure its
advanced settings.
If you only want the Switch to function as a basic
layer 2 switch, you do not need to access the Web
interface and configure the Switch.
This chapter provides information on how the gain
access to the Web interface using the Discovery application. It also introduces the menu items and buttons
that are available on the Web interface.

■

A computer that is connected to the Switch and
that has a Web browser

Running the Discovery Application
The 3Com Baseline Switch 2250 Plus CD-ROM contains, among others, the Discovery application.
To use Discovery to connect to the Web interface, do
the following:
1 On a computer that is connected to the Switch, insert

the CD-ROM into its CD drive.

■

Requirements for Accessing the Web Interface

Discovery should start automatically. If it does not
start automatically, go to the \Discovery folder on
the CD-ROM, and then double-click discovery.exe.

■

Running the Discovery Application

The Welcome screen of Discovery appears.

■

Logging On to the Web Interface

■

Navigating the Web Interface

The following topics are covered:

Requirements for Accessing the Web Interface
To connect to the Web interface, you need the following:
■

The Discovery application, which is included on
3Com Baseline Switch 2250 Plus CD-ROM that is
supplied with your Switch

CHAPTER 3: CONNECTING TO THE WEB INTERFACE

Figure 5 Welcome Screen of Discovery

2 If the computer has multiple network adapters, select

the adapter that connects the computer to the
Switch, and then click Next.
If the computer has only one adapter, click Next.
Discovery searches the network for 3Com devices.
When detection is complete, the Discovered Devices
screen displays detected network devices.

Figure 6 Discovered Devices Screen

3 On the Discovered Devices screen, click Baseline

Switch 2250 Plus, and then click Next.
The Completing the 3Com Discovery Application
screen appears.
4 Click Finish.

The logon dialog box for the Web interface appears.

Logging On to the Web Interface
On the log on dialog box, enter the administration
user name and password to gain access to the Web
interface.

Navigating the Web Interface

Figure 7 Logon Dialog Box

Figure 8 Switch Screen Layout

Buttons

To log on to the Web interface:
1 In User name, type admin.
2 Leave the Password field blank.
3 Click OK.

Navigating the Web Interface
The Web interface has been designed to enable you
to easily perform advanced configuration tasks and
view information about the Switch.

Table 8 lists the available items on the menu.
Table 8 Available Menu Items
Menu Item
Description
Summary

Provides a summary of the Switch’s
basic settings and versions of current
components

Password

Allows you to change the administrator password

IP Settings

Allows you to configure the IP address
settings of the Switch

Menu
The menu is located on the left side of the Web interface. When you click an item on the menu, the
related screen appears in the main part of the interface.

Port Status

CHAPTER 3: CONNECTING TO THE WEB INTERFACE

Menu Item

Description

Port Configuration

Allows you to configure the Switch’s
port settings

VLANs

Allows you to create VLAN groups,
add port members, and specify how
VLAN tagging is used

Trunking

Allows you to set up and maintain
trunk membership for port groups

Traffic Monitoring

Allows you to perform port traffic
monitoring on the Switch. To monitor
a port, you will also need a network
analyzer.

System Tools

Contains tabs that allow you to:
■

Restart and reset the Switch

■

Back up and restore configuratio

■

Upgrade the firmware

■

Configure forwarding of BPDU
packets to support a spanning tree
topology

■

Enable and disable 802.1p prioritization

Support

Displays 3Com contact information
and describes how to use the online
help system

Log Out

Allows you to securely log off the
Web interface

Buttons
Depending on the screen that is currently displayed,
the following buttons may appear:
■

Apply – Click to save and apply any changes that
you have made

■

Cancel – Click to discard any unsaved changes

■

Help – Click to display the context-sensitive help
information for the screen that is currently displayed. The help pages provide information on the
tasks that you can perform on each screen.

Port Status
At the bottom of each screen is an image of the
Switch’s front panel, which indicates ports that are
currently in use.
To configure a port, click the port on the image. This
takes you to the Basic Port Configuration tab, where
you can:
■

Assign a name (or label) to the port

■

Enable or disable the port

■

Enable or disable flow control

■

Configure the speed duplex settings

Accessing the Interface Without Using
Discovery
The Discovery application works by automatically
detecting the IP address that is assigned to the
Switch, and then using that address to connect to the
Web interface. If you know the Switch’s IP address,
you can access the Web interface without using Discovery.
This section describes how to access the interface
directly, without using Discovery.

Accessing the Interface Without Using Discovery

DHCP Assigned IP Address
If you set the IP address mode to DHCP, check the
DHCP server for the IP address that is assigned to the
Switch, and then use that IP address to access the
Web interface.
For example, if the DHCP server assigned the IP
address 192.168.0.123 to the Switch, start your Web
browser, and then type http://192.168.0.123.

Manually Assigned (Static) IP Address
If you assigned a static IP address to the Switch, you
need to use that IP address to access the Web interface the next time you want to configure the Switch.
For example, if you assigned the Switch the IP address
192.168.0.123, start your Web browser, and then
type http://192.168.0.123.

CHAPTER 3: CONNECTING TO THE WEB INTERFACE

CONFIGURING THE SWITCH

This chapter provides information on how to configure the Switch’s advanced features. Topics include:
■

Viewing Summary Information

■

Changing the Admin Password

■

Modifying the IP Address Settings

■

Configuring Port Settings

■

Configuring VLANs

■

Configuring Trunking

■

Monitoring Traffic

■

Using the System Tools

■

Viewing Summary Information
The Summary screen, which automatically loads after
you log on to the Web interface, provides a snapshot
of the Switch’s basic settings and versions of current
components.
Information that you can view on the Summary
screen include:
■

System Information — Contains optional fields
that you can fill out to identify the Switch. It also
shows the object ID and the time elapsed since the
Switch was last started. After you update any of
the editable fields in this section, click Apply to
save your changes.

■

Switch Information – Shows the serial number,
total number of ports, and the version of the hardware (board) on the Switch

■

Management Software Information – Shows the
versions of the loader (firmware), boot ROM, and
code

■

IP Information – Shows the IP address settings of
the Switch. To modify any of these settings, click IP
Settings. This takes you to the IP Settings screen, as
shown in Figure 11.

Configuration Overview
The Switch is shipped ready for use. If you only want
the Switch to function as a basic layer 2 switch, you
do not need to access the Web interface and configure the Switch.
You only need to access the Web interface if you
want to:
■

Set the administration password to the Web interface

■

Assign an IP address to the Switch

■

Configure the Switch’s advanced features

Upgrade the firmware

CHAPTER 4: CONFIGURING THE SWITCH

Figure 9 Top Half of the Summary Screen

To ensure that unauthorized users do not access the
Web interface, 3Com recommends that you set an
admin password when you first configure the Switch.
Even if you do not intend to actively manage the
switch, 3Com recommends that you change the password to prevent unauthorized access to your network.
Figure 10 Change Administration Password Screen

If you request for technical assistance from 3Com
Support, you may be asked to print out the information on this screen.

To set the admin password:
1 On the menu, click Password. The Change Adminis-

tration Password screen appears.

Changing the Admin Password
To prevent unauthorized users from accessing the
Web interface and modifying the Switch’s settings,
the interface is password-protected.
The default admin account settings are:
■

User name – admin

■

Password – blank (no password)

2 In Old Password, type your current password.

By default, the Switch does not have any password. If
this is your first time to access this screen or if you
have not previously set a password, leave this field
blank.
3 In New Password, type the password that you want to

set.

Modifying the IP Address Settings

4 In Confirm Password, retype the password you typed

in step 3 to confirm.

the sticker on the base of the Switch. This sticker contains the MAC address and default IP address of the
Switch.

The password is case-sensitive.
5 Click Apply.

If you want to modify the admin password later on,
follow the same procedure.
If you forget the administration password after you
set it, refer to “Forgotten Password” on page 43 for
information on how to regain access to the Web
interface.

Modifying the IP Address Settings
To enable devices on the network to communicate
with the Switch, you need to assign an IP address to it
— either by DHCP or by assigning a static IP address.
By default, the Switch performs automatic IP configuration and assigns an IP address to itself. This is necessary for the Discovery application to be able to
connect to the Web interface.

Automatic IP Configuration
When you power on the Switch for the first time, it
automatically uses the default IP address
169.254.x.y, where x and y are the last two bytes of
its MAC address.
To determine the exact IP address that the Switch
assigns to itself during auto IP configuration, check

To detect its IP information using the automatic configuration process, the Switch goes through the following sequence of steps:
1 The Switch tries to configure itself with the default IP

address 169.254.x.y, where x and y are converted
from the last two bytes of its MAC address.
For example, if the MAC address is 08004E000102, the
IP address would be 169.254.1.2. This address is used
if the Switch is operating in a standalone mode, or no
other switches on the network have this IP address.
The Switch also assigns the subnet mask 255.255.0.0
(default class B mask) to itself.
2 If this default IP address is already in use on the net-

work, then the Switch detects this, and increments
the last byte of the MAC address by one to generate
its IP address.
The IP address would therefore become 169.254.1.3.
3 The Switch repeats step 2 until an unused IP address

is found.
3Com recommends using automatic IP configuration
only for the initial setup. Once you gain access to the
console, you should assign an IP address to the Switch
(either by using DHCP or assigning a static IP address)
to ensure successful communication between the
Switch and other network devices.

CHAPTER 4: CONFIGURING THE SWITCH

Setting the IP Address
To set the IP address for the Switch:
1 Click IP Settings on the menu. The IP Settings screen

Table 9 IP Setting Options
Option
Description
IP Address Mode

appears.

Specify how the Switch will get its IP
address. Available options include:
■

DHCP – Select this option if you have
a DHCP server on the network and
you want the Switch to automatically
obtain an IP address from it

■

Static – Select this option if you want
to manually assign an IP address to
the Switch

Figure 11 IP Settings Screen

IP Address

Specify an IP address that you want to
assign to the Switch. This option is only
available if IP Address Mode is set to
Static.
The IP address that is assigned to the
Switch also becomes the IP address for
VLAN 1.

Subnet Mask

2 Configure the Switch’s IP settings. Available options

are listed in Table 9.

Specify a subnet mask address that you
want to assign to the Switch. This option
is only available if IP Address Mode is set
to Static.
The default subnet mask is
255.255.0.0.

Default Gateway

Specify the IP address of the gateway
router between this Switch and management stations on other network segments. This option is only available if IP
Address Mode is set to Static.

MAC Address

Read-only field that displays the Switch’s
MAC or physical address

3 After you configure the Switch’s IP address settings,

click Apply to save your changes.

Configuring Port Settings

Configuring Port Settings
Using the Web interface, you can configure the
speed/duplex and flow control settings of each port.
You can also view the current connection status of
each port or shut down or disable ports.
Two tabs are available on the Port Configuration
page:
■

Basic Port Configuration

■

Advanced Port Configuration

Basic Port Configuration
Use the Basic Port Configuration tab to enable and
disable the port and its flow control settings and to
set the speed/duplex of the port.

■

Speed Duplex – Sets the speed and duplex mode
of the port. Available options include auto, 10
half-duplex, 10 full-duplex, 100-half duplex, and
100 full-duplex. For 1000 Mbps connections, see
“Speed/Duplex for 1000 Mbps Connections”
below.
Auto (or autonegotiation), which is enabled by
default, sets the optimum combination of speed
and duplex that can be supported by both ends of
the link.

If you modify any of these settings, click Apply to save
your changes.
Figure 12 Basic Port Configuration Screen

The following options are available:
■

Number – Physical port number

■

Label – Optional name for the port to help you
identify the device connected to it. For example, if
an access point is connected to this port, you can
label it as Access Point.

■

Status – Enables and disables the port

■

Flow Control – Enables and disables flow control
on the port. When flow control is enabled for the
port, the Switch regulates the packet flow so that
a sending device does not transmit more packets
than a receiving device can process. If flow control
is disabled, packets may be dropped under certain
periods of high traffic.
Flow control is enabled by default.

Speed/Duplex for 1000 Mbps Connections
You cannot preset the speed to 1000Mbps. To run a
port at 1000Mbps, you must enable autonegotiation
for the port. When autonegotiation is enabled, the

CHAPTER 4: CONFIGURING THE SWITCH

Switch will automatically connect at 1000Mbps, providing the connected device also supports this speed.
1000Mbps connections are always full-duplex.
Half-duplex connections are only available for
10Mbps and 100Mbps settings.
CAUTION: Before manually setting a port to
full-duplex, verify that the device connected to the
port is also manually set to the same speed and
duplex setting. If connecting link partners are left to
autonegotiate for a link manually set on this switch to
full-duplex, they will always negotiate to half-duplex,
resulting in a duplex mismatch. This can result in a
significant reduction in network performance. If you
are unsure of how to configure the speed/duplex setting, simply enable autonegotiation for the port.
You cannot modify the speed/duplex settings of ports
that are members of a trunk or aggregated link.
Supported SFP transceivers only operate at 1000Mbps
full-duplex. Inserting an SFP transceiver into a gigabit
port disables the corresponding RJ-45 port, even if no
fiber cable is inserted.

Advanced Port Configuration
Use the Advanced Port Configuration tab to set the
Switch’s broadcast storm control and threshold limits.
A broadcast storm is an incorrect packet sent out on a
network that causes most hosts to respond all at
once, typically with wrong answers that start the process over again. Broadcast storms use substantial network bandwidth and may cause network time-outs.

Advanced settings include:
■

Broadcast Storm Control – Enables and disables
broadcast storm control

■

Packet Rate Threshold – Sets the broadcast storm
threshold (64 to 95232000 bytes per packet)

Figure 13 Advanced Port Configuration Screen

Default Port Settings
If you do not configure the Switch’s port settings, the
ports will use the following default settings:
■

All ports are enabled

■

Autonegotiation is enabled

■

Flow control is enabled

■

All ports are set to priority zero

Configuring VLANs
You can use the Switch to create VLANs to organize
any group of ports into separate broadcast domains.
VLANs confine broadcast traffic to the originating
group and help eliminate broadcast storms in large

Configuring VLANs

networks. This also provides for a more secure and
cleaner network environment.
You can create up to 256 VLANs, add specific ports to
a chosen VLAN (so that the port can only communicate with other ports on the VLAN), or configure a
port make it a member of all VLANs.
Communication between different VLANs can only
take place if they are all connected to a router or layer
3 switch.

For examples on setting up VLANs, refer to “Sample
VLAN Configurations”.
CAUTION: At least one port must always be a
member of VLAN 1 (the management VLAN). If you
choose to connect all ports to VLANs other than
VLAN 1, you will no longer be able to access the Web
interface. If this happens, you will need to reset the
Switch to factory settings.
By default, all ports belong to VLAN 1.

Creating a VLAN
Use the Create VLANs screen to create VLANs on the
Switch. To propagate information about VLAN
groups used on this Switch to external devices, you
must specify a VLAN ID for each VLAN.

Deleting VLANs
Use the Delete screen to remove a VLAN group from
the current list.
Figure 15 Delete Screen

Figure 14 Create VLANs Screen

Available options on the Create VLAN screen include:
■

VLAN ID – ID of configured VLAN (1-4094, no
leading zeroes)

■

Name – Name of the VLAN (1 to 32 characters)

■

VLAN ID – ID of the VLAN to be deleted. If any port
is assigned to this group as untagged, it will be
reassigned to VLAN group 1 as untagged.

CHAPTER 4: CONFIGURING THE SWITCH

Modifying VLANs
Use the Modify VLAN screen to change the VLAN to
which a port belongs, and configure the port to communicate with all other VLANs, or a selected VLAN.

■

Desktop - If you select this, the port can only communicate with other ports assigned to the VLAN
selected in the VLAN ID drop-down list.

An uplink port is sometimes referred to as a tagged
port. The two terms refer to the same feature.

Figure 16 Modify VLANs Screen
■

VLAN ID – Enter the ID of the configured VLAN to
which you want this port to belong

Defining VLAN Membership
Use the Membership screen to configure port members for the selected VLAN.
Figure 17 Membership Screen

■

Port – Displays the port number

■

Mode – The mode option determines if the port
can communicate with all VLANs, or only with a
selected VLAN

■

Uplink – If you select this, the port is able to communicate with all VLANs on the Switch

■

VLAN ID – ID of the configured VLAN (1-4094, no
leading zeroes)

■

Name – Name of the VLAN (1 to 32 characters)

■

Ports – Port identifier

Sample VLAN Configurations
To illustrate how you can segment network devices
that are connected to the Switch, the following
sample configurations are provided.

Configuring VLANs

Setting Up Two VLANs on the Same Switch
Figure 18 illustrates how you can set up a simple
VLAN on the Switch using desktop connections.
Figure 18 Desktop VLAN Configuration
Endstations
in VLAN 1

Endstations
in VLAN 2

Port 1
Port 3

Baseline
Baseline
Switch
Switch
2250 2250 Plus

Port 26

Server
in VLAN 2

Server
in VLAN 1

If you want to add ports 1, 3, and 26 to VLAN2 (as
shown in Figure 18), so that the ports on the default
VLAN1 and the ports on VLAN2 cannot communicate
with each other, do the following:
1 Create a new VLAN and set the VLAN ID to 2. Refer

to “Creating a VLAN” for instructions. VLAN1 is the
default VLAN and already exists.
2 Set ports 1, 3, and 26 to Desktop mode.
3 Click Apply.

Ports 1, 3, and 26 now belong to VLAN2, and will not
communicate with any other ports, unless you add
other ports to the VLAN or change the port configuration.
Setting Up VLAN Across Two Switches
This example explains how you can set up a VLAN
across two Switches using uplink connections. This
enables ports that are members of the same VLAN
(but are on different switches) to communicate, provided that a port on each Switch is set to uplink, and
that these ports are connected.

CHAPTER 4: CONFIGURING THE SWITCH

Figure 19 Uplink VLAN Configuration
Endstation
in VLAN 1 (Desktop)

Server
in VLAN 1 (Desktop)

Endstation
in VLAN 2
(Desktop)

Click Apply.
4 Connect the uplink port on Switch 1 (in this example,

port 16) to the uplink port on Switch 2 (in this example, port 8).
Those ports on Switch 1 that are members of VLAN2
can now communicate with those ports on Switch 2
that are members of VLAN2.

Switch 1
Switch 2

Port 16 in VLANs 1 and 2 (Uplink)
Port 8 in VLANs 1 and 2 (Uplink)

Endstation
in VLAN 2
(Desktop)
Server
in VLAN 2 (Desktop)
Endstation
in VLAN 1 (Desktop)

To set up the configuration shown in Figure 19, do
the following:
1 Create VLAN2 on both Switch 1 and Switch 2, and

assign the same name to it. You need not create
VLAN1 since it exists by default.
2 On Switch 1, set the ports that you want to be part of

VLAN2 to Desktop mode. Set one port (for example,
port 16) to Uplink mode.
Click Apply.
3 On Switch 2, set the ports that you want to be part of

VLAN2 to Desktop mode. Set one port (for example,
port 8) to Uplink mode.

Configuring Trunking
Trunking, also called “link aggregation”, refers to
bonding multiple ports into a single group to effectively combine the bandwidth into a single connection or a “trunk”. If you are connecting the Switch to
another switch or to an Internet backbone, you can
aggregate links on the Switch to increase throughput
and prevent packet loopback between switches.
For link aggregation to work, the trunks must be configured on both ends (switches).
The Switch does not support the Link Aggregation
Control Protocol (LACP), which is specified in IEEE
802.3ad.

Guidelines for Creating Trunks
■

Any port on the Switch can be used for creating a
trunk.

■

This switch supports a maximum of four trunks.

■

Each trunk may contain up to eight members.

■

A port may only be a member of one trunk at any
one time.

Configuring Trunking

■

All ports in a trunk must be configured in an identical manner, including communication mode (that
is, speed, duplex mode and flow control).

Figure 21 Membership Screen

Creating, Modifying, and Deleting Trunks
Use the Modify/Delete tabe under Trunking to create,
configure or remove ports groups from trunks.
Figure 20 Modify/Delete Screen

■

Trunk Number – Displays the number of the trunk.

■

Name – Allows you to label an interface. (Range:
1-64 characters)

■

Flow Control – Allows automatic or manual selection of flow control.
Speed Duplex – Allows auto-negotiation to be
enabled or disabled. When auto-negotiation is disabled, you can force the settings for speed, duplex
mode and flow control.

Defining Trunk Membership
Use the Membership screen to add ports to a group
membership.

■

Port – The port number

■

Status – The status refers to the speed and duplex
mode of the trunk members

■

Trunk – ID of trunk

Viewing Trunk Information
To view information on the configuration settings for
the created trunks, click the Summary tab underTrunking.

CHAPTER 4: CONFIGURING THE SWITCH

Figure 22 Summary Screen

To set up traffic monitoring for a port:
1 Connect a network analyzer to a port.
2 Access the Web interface, and then click Traffic Mon-

itoring on the menu. The Port Traffic Monitoring
Screen appears.
3 On the Monitor Port menu, select the port number

that you want to monitor.
4 On the Analyzer Port menu, select the port number to

Monitoring Traffic
The Switch allows you to monitor traffic going in and
out of a particular port. For traffic monitoring to
work, you need to attach a network analyzer to one
port and use it to monitor the traffic of other ports in
the stack.
To set up traffic monitoring, you need to set an analysis port (the port that is connected to the analyzer),
and a monitor port (the port that is to be monitored).
Once the pair is defined, and you enable traffic monitoring, the Switch takes all the traffic going in and
out of the monitor port and copies it to the analysis
port.
CAUTION: The analyzer port should have a higher
bandwidth than the mirror port. Otherwise, the
Switch may not be able to copy all traffic effectively
during periods of high traffic.

which you connected the network analyzer. Traffic to
and from the port selected in Monitor Port will be forwarded to this port.
Figure 23 Port Traffic Monitoring Screen

Only one port can be selected from the Mirror Form
row, which means that you can only monitor one port
at any given time.
5 In Mirror Type, select the type of packet that you

want to monitor.
You can monitor only one type of packet at a time.
Select either TX or RX from the Mirror Type
drop-down menu.
6 Click Apply.

Using the System Tools

For information on how to interpret the output on
the port analyzer, refer to its accompanying documentation.

Using the System Tools
The System Tools menu includes five administration
items:
■

Restart

■

Configuration

■

Upgrade

■

Spanning Tree

■

802.1p Prioritization

Any network users that are currently accessing the
Internet will have their access interrupted while the
restart takes place, and they may need to reboot their
computers when the restart has completed and the
Switch is operational again.

Resetting and Backing Up/Restoring Configuration
Select the Configuration tab to display the Configuration screen.
Figure 25 Configuration Screen

Restarting the Switch
Pressing the Restart the Switch button has the same
effect as power cycling the unit. No configuration
information will be lost. Restart the Switch if you are
experiencing problems and you want to re-establish
your Internet connection.
Figure 24 Restart Screen

■

Click BACKUP to save the current configurations of
the Switch. You will be prompted to download
and save a file to disk.

CHAPTER 4: CONFIGURING THE SWITCH

■

To reload configuration settings that you previously saved to a file, scroll down the page, and
then click Browse to locate the backup file on your
computer, and then RESTORE to copy the configuration back to the Switch.

Figure 26 Upgrade Screen

For security purposes, restoring the configuration
does not change the password.
■

If you want to reset the settings on your Switch to
those that were loaded at the factory, click RESET.
You will lose all your configuration changes. The
Switch LAN IP address will revert to the default IP
address 169.254.x.y. (see “Automatic IP Configuration” on page 29). You may need to restart your
computer to re-establish communication with the
Switch.

Upgrading the System Software
The Upgrade facility allows you to install on the
Switch any new releases of system software that
3Com may make available.
Newer versions of software can be downloaded via
HTTP and copied to the Switch; the Switch will restart
and apply the newer system software version.

Once you have downloaded the software, use the
Browse button to locate the file on your computer,
and then click Apply.
You may need to change the file type in the dialog
box displayed by your Web browser to *.* to be able
to see the file.
The file will be copied to the Switch, and once this
has completed, the Switch will restart. Although the
upgrade process has been designed to preserve your
configuration settings, 3Com recommends that you
make a backup of the configuration beforehand, in
case the upgrade process fails for any reason (for
example, the connection between the computer and
the Switch is lost while the new software is being
copied to the Switch).
A progress screen displays while the upgrade is taking
place.
The upgrade procedure can take a few minutes, and
is complete when the progress bar has finished running and the Power LED has stopped flashing and is
permanently green.

Using the System Tools

CAUTION: Do not interrupt power to the Switch
during the upgrade procedure. If you do, the software may be corrupted and the Switch may not start
up properly afterwards.

Configuring the Spanning Tree
This administrative tool supports the configuration of
the Switch to forward, or block and discard 802.1D
spanning tree BPDU packets.
Spanning tree is a bridge-based system for providing
fault tolerance on networks and can be used to
detect and disable network loops. The spanning tree
ensures that the optimal path is maintained between
spanning tree-compliant networked devices by:
■

Disabling redundant paths when the main paths
are operational.

■

Enabling redundant paths if the main paths fail.

Spanning tree uses a distributed algorithm to select a
bridging device that serves as the root of the spanning tree network. The bridging device, known as the
Root Bridge, generates bridge protocol data units
(BPDUs) on all ports at a regular interval known as the
Hello Time. All other spanning tree-compliant devices
on the network have a designated Root Port. This is
the Port nearest the Root Bridge and it is used for
receiving the BPDUs initiated by the Root Bridge. If a
bridge does not get a Hello BPDU after a predetermined interval, the bridge assumes that the link to the
Root Bridge is down. This bridge will then initiate
negotiations with other bridges to reconfigure the
network to reestablish a valid network topology.

After all the bridges on the network have determined
the configuration of their ports, each bridge only forwards traffic between the Root Port and the ports
that are the Designated Bridge Ports for each network
segment. All other ports are blocked, which means
that they are prevented from forwarding traffic.
Figure 27 Spanning Tree Screen

■

Forward – Spanning tree BPDU packets received on
a port are forwarded to all other ports

■

Block and Discard – Spanning tree BPDUs received
on a port are dropped. The Switch does not forward BPDUs to other ports.

The Switch does not participate as a bridge node in
the spanning tree, it can only be configured to forward or block spanning tree BPDUs. If the Switch is
connected to other bridging devices, such as
switches, that are part of the spanning tree network,
set the Switch to "Forward." If the Switch is connected only to workstations, it can be set to "Block
and Discard."

802.1p Prioritization
The Switch has priority queuing enabled, which
means all packets that are received are examined to
see if they have been priority encoded. If a packet has

CHAPTER 4: CONFIGURING THE SWITCH

been priority encoded, then the Switch will read the
priority level and determine whether the packet
should be directed through the normal or high priority channel. This feature can be useful for example
during excessive loads when one type of traffic may
require priority over another.
The Switch is configured to comply with 802.1p,
VLAN tagged frames.
Traffic prioritization ensures that high priority data is
forwarded through the Switch without being delayed
by lower priority data. It differentiates traffic into
classes and prioritizes those classes automatically.
Traffic prioritization uses the multiple traffic queues
that are present in the hardware of the Switch to
ensure that high priority traffic is forwarded on a different queue from lower priority traffic, and is given
preference over that traffic. This ensures that
time-sensitive traffic gets the highest level of service.

Video (interactive media), less than 100
milliseconds latency and jitter

Voice (interactive voice), less than 10 milliseconds latency and jitter.

Network control reserved traffic

The traffic prioritization feature supported by the
Switch is compatible with the relevant sections of the
IEEE 802.1D standard (incorporating IEEE 802.1p).
This switch uses the Weighted Round Robin (WRR)
algorithm to determine the frequency at which it services each priority queue. The Switch allows you to
choose between using IP Precedence or DSCP (Differentiated Services Code Point) priority. When either of
these services is enabled, the priorities are mapped to
a Class of Service value by the Switch, and the traffic
then sent to the corresponding output queue.
Figure 28 802.1p Prioritization Screen

The 802.1D standard specifies eight distinct levels of
priority (0 to 7), each of which relates to a particular
type of traffic. The priority levels and their traffic types
are shown in the following table.
Table 10 Priority Levels for Traffic Types
Priority Level
Traffic Type
0

Best effort

Background

Standard (spare)

Excellent effort (business critical)

Controlled load (streaming multimedia)

TROUBLESHOOTING

This chapter lists some issues that you may encounter
while installing, using, and managing the Switch,
with suggested courses of corrective action to take.
If you encounter an issue that is not listed here and
you cannot solve it, check the 3Com Knowledgebase
at http://knowledgebase.3com.com before contacting
your local technical support representative.
For more information on how to obtain support for
your Switch, refer to Appendix A.

Resetting to Factory Defaults
If the Switch does not operate normally or if the firmware becomes corrupted, you can reset the Switch to
factory defaults.

4 Reset the Switch either by:
■

Accessing the Web interface using Discovery, and
then pressing the RESET button on the Configuration tab (see Figure 29) of System Tools. After you
click RESET, a confirmation message appears. Click
OK to confirm.

■

Powering off the Switch, and then powering it
back on.

The Switch will perform automatic IP configuration
after you reset it. See “Automatic IP Configuration”
on page 29 for more information.
Figure 29 Configuration Tab

CAUTION: Resetting the Switch to factory defaults
erases all your settings. You will need to reconfigure
the Switch after you reset it.
To reset the Switch to its factory defaults:
1 Using the tip of a pen (or a similar object), press the

Recovery button on the rear panel of the Switch. See
Figure 1 for illustration.
2 Power off the Switch, and then power it back on,

while keeping the Recovery button pressed.
3 Release the Recovery button.

Forgotten Password
If you forget the password to the Web interface after
you set it, you will need to reset the Switch to regain

CHAPTER 5: TROUBLESHOOTING

access. See “Resetting to Factory Defaults” on
page 43 for instructions.
After resetting the Switch, log on to the Web interface using the default admin account settings:
■

User name – admin

■

Password – blank (no password)

Forgotten Static IP Address
If you forget the static IP address that you assigned to
the Switch and you need to access the Web interface,
use the Discovery application to automatically detect
the IP address and connect to the interface.

A link is connected, but the Link/Activity LED for
the port is off.
There is a problem with this connection. Verify that:
■

The device being connected to is powered on and
operating correctly.

■

The cable is connected at both ends.

■

The cable is not damaged.

■

If the connection is to a workstation, that the
workstation's network interface is installed and
configured correctly.

■

The correct category of cable is being used for the
required link speed. Category 3 cables can be used
for 10BASE-T operation only. Category 5 cable is
required for 100BASE-TX or 1000BASE-T. 3Com
recommends Category 5e or 6 cables for
1000BASE-T operation.

For information on using the Discovery application,
refer to “Running the Discovery Application” on
page 21.

Solving LED Issues
This section lists some issues that are related to the
LEDs on the front panel of the Switch. For information on basic LED checks, refer to the following topics
in Chapter 1:
■

(4) Module Active LEDs

■

(4) Module Active LEDs

■

(3) Link/Activity LEDs

■

(5) Power LED

A fiber cable is connected, but the Module
Active LED is off.
Verify that:
■

The fiber cable is in good condition.

■

The SFP module is correctly inserted.

■

A 3Com SFP module is being used. Refer to
“Approved SFP Transceivers” on page 18 for
details.

■

The equipment at the far end is installed and correctly configured.

The Link/Activity LED is on, but network performance is poor

If the Problem Persists

The Switch supports full-duplex autonegotiation. If
the connected device does not support autonegotiation, ensure that it is configured for half-duplex operation only. If the connected device has
autonegotiation disabled or overridden, and is configured as full-duplex, the Switch will configure the link
as half-duplex, causing a mismatch that will reduce
network performance when data is transmitting and
receiving simultaneously on the same link.
Ensure that the connected device has either:
■

Autonegotiation enabled, or

■

The ports are configured for half-duplex operation

All ports appear to show continual activity.
There may be broadcast storms on the network.
Remove port connections one at a time, waiting a
few seconds between each port. If the LEDs go off
after removing a port connection, the device that was
connected to that port is introducing an excessive
amount of broadcast frames to the network. Some
pieces of network equipment operate by sending out
broadcast frames regularly.
Refer to the documentation that accompanies the
device for information on disabling the broadcast
operation.

If the Problem Persists
If the problem persists and the unit still does not
operate successfully, contact your 3Com network
supplier with the following information before returning the unit:

■

Product number and serial number (printed on a
label supplied with the unit).

■

A brief description of the issue

CHAPTER 5: TROUBLESHOOTING

OBTAINING SUPPORT FOR YOUR PRODUCT

Register Your Product
Warranty and other service benefits start from the
date of purchase, so it is important to register your
product quickly to ensure you get full use of the warranty and other service benefits available to you.
Warranty and other service benefits are enabled
through product registration. Register your product at
http://eSupport.3com.com/. 3Com eSupport
services are based on accounts that you create or
have authorization to access. First time users must
apply for a user name and password that provides
access to a number of eSupport features including
Product Registration, Repair Services, and Service
Request. If you have trouble registering your product,
please contact 3Com Global Services for assistance.

projects. More information on 3Com maintenance
and Professional Services is available at
http://www.3com.com/
Contact your authorized 3Com reseller or 3Com for a
complete list of the value-added services available in
your area.

Troubleshoot Online
You will find support tools posted on the 3Com web
site at http://www.3com.com/
3Com Knowledgebase helps you troubleshoot
3Com products. This query-based interactive tool is
located at http://knowledgebase.3com.com and
contains thousands of technical solutions written by
3Com support engineers.

Purchase Value-Added Services
To enhance response times or extend warranty benefits, contact 3Com or your authorized 3Com reseller.
Value-added services like 3Com ExpressSM and GuardianSM can include 24x7 telephone technical support,
software upgrades, onsite assistance or advance
hardware replacement. Experienced engineers are
available to manage your installation with minimal
disruption to your network. Expert assessment and
implementation services are offered to fill resource
gaps and ensure the success of your networking

Access Software Downloads
Software Updates are the bug fix / maintenance
releases for the version of software initially purchased
with the product. In order to access these Software
Updates you must first register your product on the
3Com web site at http://eSupport.3com.com/.
First time users will need to apply for a user name and
password. A link to software downloads can be

APPENDIX A: OBTAINING SUPPORT FOR YOUR PRODUCT

found at http://eSupport.3com.com/, or under
the Product Support heading at
http://www.3com.com/

Software Upgrades are the software releases that
follow the software version included with your original product. In order to access upgrades and related
documentation you must first purchase a service contract from 3Com or your reseller.

To send a product directly to 3Com for repair, you
must first obtain a return authorization number
(RMA). Products sent to 3Com, without authorization
numbers clearly marked on the outside of the package, will be returned to the sender unopened, at the
sender’s expense. If your product is registered and
under warranty, you can obtain an RMA number
online at http://eSupport.3com.com/. First time
users will need to apply for a user name and password.

Telephone Technical Support and Repair
To obtain telephone support as part of your warranty
and other service benefits, you must first register your
product at http://eSupport.3com.com/
Warranty and other service benefits start from the
date of purchase, so it is important to register your
product quickly to ensure you get full use of the warranty and other service benefits available to you.
When you contact 3Com for assistance, please have
the following information ready:
■

Product model name, part number, and serial
number

■

Proof of purchase, if you have not pre-registered
your product

■

A list of system hardware and software, including
revision level

■

Diagnostic error messages

■

Details about recent configuration changes, if
applicable

Contact Us
3Com offers telephone, e-mail and internet access to
technical support and repair services. To access these
services for your region, use the appropriate telephone number, URL or e-mail address from the list
below.
Telephone numbers are correct at the time of publication. Find a current directory of support telephone
numbers posted on the 3Com web site at
http://csoweb4.3com.com/contactus/

.
Country

Telephone Number

Asia, Pacific Rim Telephone Technical Support and
Repair
Australia
Hong Kong
India
Indonesia
Japan
Malaysia
New Zealand
Pakistan
Philippines
P.R. of China
Singapore
S. Korea
Taiwan
Thailand

1 800 678 515
800 933 486
+61 2 9424 5179 or
000800 6501111
001 803 61 009
00531 616 439 or
03 3507 5984
1800 801 777
0800 446 398
+61 2 9937 5083
1235 61 266 2602 or
1800 1 888 9469
800 810 3033
800 6161 463
080 333 3308
00801 611 261
001 800 611 2000

You can also obtain support in this region using the following
e-mail: apr_technical_support@3com.com

Country

Telephone Number

Austria
Belgium
Denmark
Finland
France
Germany
Hungary
Ireland
Israel
Italy
Luxembourg
Netherlands
Norway
Poland
Portugal
South Africa
Spain
Sweden
Switzerland
U.K.

01 7956 7124
070 700 770
7010 7289
01080 2783
0825 809 622
01805 404 747
06800 12813
1407 3387
1800 945 3794
199 161346
342 0808128
0900 777 7737
815 33 047
00800 441 1357
707 200 123
0800 995 014
9 021 60455
07711 14453
08488 50112
0870 909 3266

You can also obtain support in this region using the following
URL: http://emea.3com.com/support/email.html

Or request a repair authorization number (RMA) by fax using
this number: +65 543 6348

Country

Europe, Middle East, and Africa Telephone Technical
Support and Repair

From the Caribbean, Central and South America, call:

From anywhere in these
regions, call:

+44 (0)1442 435529

From the following countries, you may use the numbers
shown:

Telephone Number

Latin America Telephone Technical Support and
Repair

APPENDIX A: OBTAINING SUPPORT FOR YOUR PRODUCT

Country

Telephone Number

Country

Telephone Number

Antigua
Argentina
Aruba
Bahamas
Barbados
Belize
Bermuda
Bonaire
Brazil
Cayman
Chile
Colombia
Costa Rica
Curacao
Ecuador
Dominican Republic
Guatemala
Haiti
Honduras
Jamaica
Martinique
Mexico
Nicaragua
Panama
Paraguay
Peru
Puerto Rico
Salvador
Trinidad and Tobago
Uruguay
Venezuela
Virgin Islands

1 800 988 2112
0 810 444 3COM
1 800 998 2112
1 800 998 2112
1 800 998 2112
52 5 201 0010
1 800 998 2112
1 800 998 2112
0800 13 3COM
1 800 998 2112
AT&T +800 998 2112
AT&T +800 998 2112
AT&T +800 998 2112
1 800 998 2112
AT&T +800 998 2112
AT&T +800 998 2112
AT&T +800 998 2112
57 1 657 0888
AT&T +800 998 2112
1 800 998 2112
571 657 0888
01 800 849CARE
AT&T +800 998 2112
AT&T +800 998 2112
54 11 4894 1888
AT&T +800 998 2112
1 800 998 2112
AT&T +800 998 2112
1 800 998 2112
AT&T +800 998 2112
AT&T +800 998 2112
57 1 657 0888

You can also obtain support in this region using the following:
Spanish speakers, enter the URL:
http://lat.3com.com/lat/support/form.html
Portuguese speakers, enter the URL:
http://lat.3com.com/br/support/form.html
English speakers in Latin America should send e-mail to:
lat_support_anc@3com.com
US and Canada Telephone Technical Support and Repair
1 800 876 3266

SAFETY INFORMATION

which it is connected also operates under SELV
conditions.

Important Safety Information
Please read the following safety information carefully
before installing the 3Com Baseline Switch 2250 Plus.

France and Peru Only
This unit cannot be powered from IT† supplies. If your
supplies are of IT type, this unit must be powered by
230 V (2P+T) via an isolation transformer ratio 1:1,
with the secondary connection point labelled Neutral,
connected directly to earth (ground).

WARNING: Installation and removal of the unit must
be carried out by qualified personnel only.
■

If installing the Switch unit in a stack with other
units, the Switch unit must be installed below the
narrower units and above the deeper units.

■

The unit must be connected to an earthed
(grounded) outlet to comply with international
safety standards.

■

Do not connect the unit to an AC outlet (power
supply) without an earth (ground) connection.

■

The appliance coupler (the connector to the unit
and not the wall plug) must have a configuration
for mating with an EN60320/IEC320 appliance
inlet.

■

The socket outlet must be near to the unit and
easily accessible. You can only remove power from
the unit by disconnecting the power cord from the
outlet.

■

This unit operates under SELV (Safety Extra Low
Voltage) conditions according to IEC 60. The conditions are only maintained if the equipment to

†

Impédance à la terre

APPENDIX B: SAFETY INFORMATION

Power Cord Set

WARNING: Fiber Optic Ports – Optical Safety

This must be approved for the country where it will
be used.
U.S.A. and Canada

■

The cord set must be UL-approved
and CSA certified.

■

The minimum specifications for the
flexible cord are:
No. 18 AWG
Type SV or SJ
3-conductor

■

The cord set must have a rated current capacity of at least 10 A.

■

The attachment plug must be an
earth-grounding type with a NEMA
5-15P (15 A, 125 V) or NEMA 6-15P
(15 A, 250 V) configuration.

Never look at the transmit laser while it is powered
on. Never look directly at the fiber ports and fiber
cable ends when they are powered on.
WARNING: Use of controls or adjustments of performance or procedures other than those specified
herein may result in hazardous laser emissions.

Consignes Importantes de Sécurité

Denmark

The supply plug must comply with Section 107-2-D1, Standard DK2-1a or
DK2-5a.

Veuillez lire à fond l'information de la sécurité suivante avant d'installer le Baseline Switch 2250 Plus.

Switzerland

The supply plug must comply with
SEV/ASE 1011.

AVERTISSEMENT: L’installation et la dépose de ce
groupe doivent être confiés à un personnel qualifié.

■

The supply plug must comply with
BS1363 (3-pin 13-amp) and be fitted
with a 5 A fuse which complies with
BS1362.

■

Si vous entassez l’unité Switch avec les unités
SuperStack 3 Hub, l’unité 2900 doit être installée
en dessous des unités Hub plus étroites.

■

The mains cord must be or
marked and be of type
HO3VVF3GO.75 (minimum).

■

Ne branchez pas votre appareil sur une prise secteur (alimentation électrique) lorsqu'il n'y a pas de
connexion de mise à la terre (mise à la masse).

■

The supply plug must comply with
CEE7/7 (“SCHUKO”)

■

Vous devez raccorder ce groupe à une sortie mise
à la terre (mise à la masse) afin de respecter les
normes internationales de sécurité.

■

Le coupleur d’appareil (le connecteur du groupe et
non pas la prise murale) doit respecter une configuration qui permet un branchement sur une entrée
d’appareil EN60320/IEC 320.

Europe

■

The mains cord must be or
marked and be of type
HO3VVF3GO.75 (minimum).

Consignes Importantes de Sécurité

■

La prise secteur doit se trouver à proximité de
l’appareil et son accès doit être facile. Vous ne
pouvez mettre l’appareil hors circuit qu’en débranchant son cordon électrique au niveau de cette
prise.

Cordon électrique
Il doit être agréé dans le pays d’utilisation.
Etats-Unis et
Canada:

L’appareil fonctionne à une tension extrêmement
basse de sécurité qui est conforme à la norme
IEC60950. Ces conditions ne sont maintenues que
si l’équipement auquel il est raccordé fonctionne
dans les mêmes conditions.

France et Pérou Uniquement
Ce groupe ne peut pas être alimenté par un dispositif
à impédance à la terre. Si vos alimentations sont du
type impédance à la terre, ce groupe doit être alimenté par une tension de 230 V (2 P+T) par le biais
d’un transformateur d’isolement à rapport 1:1, avec
un point secondaire de connexion portant l’appellation Neutre et avec raccordement direct à la terre
(masse).

■

Le cordon doit avoir reçu l’homologation
des UL et un certificat de la CSA.

■

Le cordon souple doit respecter, à titre
minimum, les spécifications suivantes:
calibre 18 AWG
type SV ou SJ
à 3 conducteurs

■

Le cordon doit être en mesure d’acheminer
un courant nominal d’au moins 10 A.

■

La prise femelle de branchement doit être
du type à mise à la terre (mise à la masse)
et respecter la configuration NEMA 5-15P
(15 A, 125 V) ou NEMA 6-15P (15 A, 250
V).

Danemark:

La prise mâle d’alimentation doit respecter la
section 107-2 D1 de la norme DK2 1a ou
DK2 5a.

Suisse:

La prise mâle d’alimentation doit respecter la
norme SEV/ASE 1011.

Europe

■

La prise secteur doit être conforme aux
normes CEE 7/7 (“SCHUKO”)

■

LE cordon secteur doit porter la mention
ou et doit être de type
HO3VVF3GO.75 (minimum).

APPENDIX B: SAFETY INFORMATION

AVERTISSEMENT: Ports pour fibres optiques – sécurité sur le plan optique

■

Das Gerät muß an eine geerdete Steckdose angeschlossen werden, welche die internationalen
Sicherheitsnormen erfüllt.

■

Ne regardez jamais le laser tant qu'il est sous tension.
Ne regardez jamais directement le port à fibres
optiques et les embouts de câbles à fibres optiques
tant qu'ils sont sous tension.

Der Gerätestecker (der Anschluß an das Gerät,
nicht der Wandsteckdosenstecker) muß einen
gemäß EN 60320/IEC 320 konfigurierten Geräteeingang haben.

■

AVERTISSEMENT: L'utilisation de contrôles, de
réglages de performances ou de procédures autres
que ceux qui sont spécifiés au sein du présent document risquent d'entraîner l'exposition à des rayonnements laser dangereux.

Die Netzsteckdose muß in der Nähe des Geräts
und leicht zugänglich sein. Die Stromversorgung
des Geräts kann nur durch Herausziehen des
Gerätenetzkabels aus der Netzsteckdose unterbrochen werden.

■

Der Betrieb dieses Geräts erfolgt unter den
SELV-Bedingungen (Sicherheitskleinstspannung)
gemäß IEC 60950. Diese Bedingungen sind nur
gegeben, wenn auch die an das Gerät angeschlossenen Geräte unter SELV-Bedingungen betrieben
werden.

Wichtige Sicherheitshinweise Informationen
Bitte unbedingt vor dem Einbauen des Baseline
Switch 2250 Plus die folgenden Sicherheitsanweisungen durchlesen.
WARNUNG: Die Installation und der Ausbau des
Geräts darf nur durch Fachpersonal erfolgen.
■

■

Wenn der Baseline Switch 2250 Plus mit anderen
3Com Hubs oder Switche gestapelt werden soll,
müssen grössere Geräte unter den schmaleren
Hubs eingebaut werden.
Das Gerät sollte nicht an eine ungeerdete Wechselstromsteckdose angeschlossen werden.

Stromkabel
Dies muss von dem Land, in dem es benutzt wird
geprüft werden.
Schweiz

■

Dieser Stromstecker muß die SEV/ASE
1011Bestimmungen einhalten.

Europe

■

Das Netzkabel muß vom Typ
HO3VVF3GO.75 (Mindestanforderung) sein und die Aufschrift
oder tragen.

■

Der Netzstecker muß die Norm CEE
7/7 erfüllen (”SCHUKO”).

Wichtige Sicherheitshinweise Informationen

WARNUNG: Die Installation und der Ausbau des
Geräts darf nur durch Fachpersonal erfolgen.

Niemals ein Übertragungslaser betrachten, während
dieses eingeschaltet ist. Niemals direkt auf die Faseransnchlüsse und auf die Faserkabelenden schauen,
während diese eingeschaltet sind.
WARNUNG: Die Verwendung von Steuerelementen
oder die Anpassung von Leistungen und Verfahren in
anderer als der hierin genannten Weise kann zu
gefährlichen Laseremissionen führen.

APPENDIX B: SAFETY INFORMATION

TECHNICAL INFORMATION

Physical

Related Standards
The 3Com Baseline Switch 2250 Plus has been
designed to the following standards:
Functional

ISO 8802-3, IEEE 802.3 (Ethernet),
IEEE 802.3u (Fast Ethernet), IEEE
802.3ab (Gigabit Ethernet), IEEE
802.3x (Flow Control), IEEE 802.1D
1998 (Bridging)

MAC Address

8192

Safety

UL60950-1, EN60950,
CSA60950-1, IEC60950

EMC Emissions

EN 55022 Class A, FCC Part 15
Subpart B Class A, ICES-003 Class
A, VCCI Class A, AS/NZS 3548
Class A, CNS 13438 Class A

Immunity

EN 55024

Environmental
Operating Temperature

0–45 °C (32–113 °F)

Humidity

10–95% (non-condensing)

Standard

EN 60068 (IEC 68)—various parts

Width

440 mm (17.3 in.)

Depth

235.5 mm (9.2 in.)

Height

43.6 mm (1.7 in.) or 1U

Weight

3.1 kgs (6.83 lbs)

Mounting

Free standing, or 19 in. rack
mounted using the mounting kit
supplied

Electrical
Power Inlet

IEC 320

AC Line Frequency

50/60 Hz

Input Voltage

100–240 VAC

Current Rating

2 amperes (maximum)

Maximum Power Consumption

56 watts

Maximum Power Dissipation

184.3 BTU/hr

APPENDIX C: TECHNICAL INFORMATION

GLOSSARY

10BASE-T
The IEEE specification for 10 Mbps Ethernet over Category 3, 4 or 5 twisted pair cable.
100BASE-TX
The IEEE specification for 100 Mbps Fast Ethernet
over Category 5 twisted-pair cable.
1000BASE-LX
IEEE 802.3z specification for Gigabit Ethernet over
9/125 micron core single-mode fiber cable.
1000BASE-SX
IEEE 802.3z specification for Gigabit Ethernet over
two strands of 50/125 or 62.5/125 micron core multimode fiber cable.
1000BASE-T
IEEE 802.3ab specification for Gigabit Ethernet over
100-ohm Category 5, 5e or 6 twisted-pair cable
(using all four wire pairs).
autonegotiation
Autonegotiation is where two devices sharing a link,
automatically configure to use the best common
speed. The order of preference (best first) is:
1000BASE-T full-duplex, 100BASE-TX full-duplex,
100BASE-TX half-duplex, 10BASE-T full-duplex, and
10BASE-T half-duplex. Autonegotiation is defined in

the IEEE 802.3 standard for Ethernet and is an operation that takes place in a few milliseconds. Autonegotiation must be enabled for the 1000BASE-T ports to
operate at 1000 Mbps, full-duplex.
bandwidth
The information capacity (measured in bits per second) that a channel can transmit. The bandwidth of
Ethernet is 10 Mbps, the bandwidth of Fast Ethernet
is 100 Mbps and Gigabit Ethernet is 1000 Mbps.
category 3 cable
One of five grades of Twisted Pair (TP) cabling defined
by the EIA/TIA-568 standard. Category 3 is voice
grade cable and can only be used in Ethernet networks (10BASE-T) to transmit data at speeds of up to
10 Mbps.
category 5 cable
One of five grades of Twisted Pair (TP) cabling defined
by the EIA/TIA-568 standard. Category 5 can be used
in Ethernet (10BASE-T) and Fast Ethernet networks
(100BASE-TX) and can transmit data at speeds of up
to 100 Mbps. Category 5 cabling is better to use for
network cabling than Category 3, because it supports
both Ethernet (10 Mbps) and Fast Ethernet (100
Mbps) speeds.

GLOSSARY

category 5e cables
One of five grades of Twisted Pair (TP) cabling defined
by the EIA/TIA-568 standard. Category 5e can be
used in Ethernet (10BASE-T), Fast Ethernet
(100BASE-TX) and Gigabit Ethernet (1000BASE-T)
networks, and can transmit data at speeds of up to
1000 Mbps.

Ethernet address
See MAC address.
Fast Ethernet
An Ethernet system that is designed to operate at 100
Mbps.
Gigabit Ethernet

category 6 cable
One of five grades of Twisted Pair (TP) cabling defined
by the EIA/TIA-568-B standard. Category 6 can be
used in Ethernet (10BASE-T), Fast Ethernet
(100BASE-TX) and Gigabit Ethernet (1000BASE-T)
networks, and can transmit data at speeds of up to
1000 Mbps.
client

An Ethernet system that is designed to operate at
1000 Mbps.
full-duplex
A system that allows packets to be transmitted and
received at the same time and, in effect, doubles the
potential throughput of a link.
half-duplex

The term used to describe the desktop PC that is connected to your network.

A system that allows packets to be transmitted and
received, but not at the same time. Half-duplex is not
supported for 1000 Mbps. Contrast with full-duplex.

DHCP
Dynamic Host Configuration Protocol. This protocol
automatically assigns an IP address for every computer on your network. Windows 95, Windows 98
and Windows NT 4.0 contain software that assigns IP
addresses to workstations on a network. These
assignments are made by the DHCP server software
that runs on Windows NT Server.
Ethernet
A LAN specification developed jointly by Xerox, Intel
and Digital Equipment Corporation. Ethernet networks use CSMA/CD to transmit packets at a rate of
10 Mbps and 100 Mbps over a variety of cables.

IEEE
Institute of Electrical and Electronics Engineers. This
American organization was founded in 1963 and sets
standards for computers and communications.
IEEE 802.1D
Specifies a general method for the operation of MAC
bridges, including the Spanning Tree Protocol.
IEEE 802.1Q
VLAN Tagging - Defines Ethernet frame tags that
carry VLAN information. It allows switches to assign
endstations to different virtual LANs, and defines a

GLOSSARY

address is written as four octets separated with periods (full-stops), and is made up of a network section,
an optional subnet section and a host section.

standard way for VLANs to communicate across
switched networks.
IEEE 802.1p
An IEEE standard for providing quality of service (QoS)
in Ethernet networks. The standard uses packet tags
that define up to eight traffic classes and allows
switches to transmit packets based on the tagged priority value.

LAN
Local Area Network. A network of end stations (such
as PCs, printers, servers) and network devices (hubs
and switches) that cover a relatively small geographic
area (usually not larger than a floor or building). LANs
are characterized by high transmission speeds over
short distances (up to 1000 meters).

IEEE 802.3ad
A standard that defines link aggregation. 802.3ad is
now incorporated into the relevant sections of the
IEEE Std. 802.3-2002.

Layer 2

Internet Engineering Task Force. An organization
responsible for providing engineering solutions for
TCP/IP networks. In the network management area,
this group is responsible for the development of the
SNMP protocol.

link aggregation

Data Link layer in the ISO 7-Layer Data Communications Protocol. This is related directly to the hardware
interface for the network devices and passes on traffic based on MAC addresses.

IETF

See Trunking.
MAC

IP
Internet Protocol. IP is a layer 3 network protocol that
is the standard for sending data through a network.
IP is part of the TCP/IP set of protocols that describe
the routing of packets to addressed devices. An IP
address consists of 32 bits divided into two or three
fields: a network number and a host number or a network number, a subnet number, and a host number.
IP Address
Internet Protocol Address. A unique identifier for a
device attached to a network using TCP/IP. The

Media Access Control. A protocol specified by the
IEEE for determining which devices have access to a
network at any one time.
MAC address
Media Access Control Address. Also called the hardware, physical, or Ethernet address. A layer 2 address
associated with a particular network device. Most
devices that connect to a LAN have a MAC address
assigned to them as they are used to identify other
devices on a network. MAC addresses are 6 bytes
long.

GLOSSARY

network
A network is a collection of computers and other
computer equipment that are connected for the purpose of exchanging information or sharing resources.
Networks vary in size, some are within a single room,
others span continents.

subnet address
An extension of the IP addressing scheme that allows
a site to use a single IP network address for multiple
physical networks.
subnet mask
A subnet mask, which may be a part of the TCP/IP
information provided by your ISP, is a set of four
numbers configured like an IP address. It is used to
create IP address numbers used only within a particular network (as opposed to valid IP address numbers
recognized by the Internet, which must assigned by
InterNIC).

ping
Packet Internet Groper. An internet utility used to
determine whether a particular IP address is online. It
is used to test and debug a network by sending out a
packet and waiting for a response.
protocol
A set of rules for communication between devices on
a network. The rules dictate format, timing, sequencing and error control.

subnet
A network that is a component of a larger network.
switch

RJ-45

A device that interconnects several LANs to form a
single logical LAN that comprises of several LAN segments. Switches are similar to bridges, in that they
connect LANs of a different type; however they connect more LANs than a bridge and are generally more
sophisticated.

A standard connector used to connect Ethernet networks. The “RJ” stands for “registered jack.”
server
A computer on a network that is shared by multiple
end stations. Servers provide end stations with access
to shared network services such as computer files and
printer queues.
SFP
Small Form Factor Pluggable (SFP) Connectors are
based on an open standard that enables hot swapping of various types of fiber optic and copper-based
transceivers into the host equipment.

TCP/IP
Transmission Control Protocol/Internet Protocol. This
is the name for two of the most well-known protocols
developed for the interconnection of networks. Originally a UNIX standard, TCP/IP is now supported on
almost all platforms, and is the protocol of the Internet.

GLOSSARY

TCP relates to the content of the data travelling
through a network — ensuring that the information
sent arrives in one piece when it reaches its destination. IP relates to the address of the end station to
which data is being sent, as well as the address of the
destination network.
traffic monitoring
Enables the monitoring of port traffic by attaching a
network analyzer to one switch port, in order to monitor the traffic of other ports on the Switch.
trunking
A method which specifies how to create a single
high-speed logical link that combines several
lower-speed physical links.
VLAN
Virtual LAN. A collection of network nodes that share
the same collision domain regardless of their physical
location or connection point in the network. A VLAN
serves as a logical workgroup with no physical barriers, and allows users to share information and
resources as though located on the same LAN.

GLOSSARY

INDEX

Numbers

1000BASE-LX 59
1000BASE-SX 59
1000BASE-T 59
100BASE-TX 59
10BASE-T 59

Ethernet 60

LAN defined 61
LED issues 44
LEDs
Link/Activity 10
Module Active 11
Power 11
link aggregation 36
local area network 61

A
auto IP configuration 29
default IP address 29
default mask 29
autonegotiation 7
autosensing 7

F
Fast Ethernet 60
forgotten IP address 43
forgotten password 43
free-standing 14
front panel
Link/Activity LEDs 10
Module Active LEDs 11
Power LED 11
RJ-45 ports 11
self-adhesive pads 12
SFP ports 10
full-duplex 60

bandwidth 59

G
C
client 60
configuration
overview 27
connecting
network device 17
SFP transceivers 18
conventions
notice icons, About This Guide 5
text, About This Guide 5

D
DHCP 60
Discovery 21
dynamic host control protocol See DHCP

Gigabit Ethernet 60

H
half-duplex 60

I
IEEE 60
IETF 61
installing 13
IP address
auto configuration 29
modifying 29
setting 30
IP defined 61

M
MAC address 61
media access control 61
monitoring traffic 38
mounting kit
contents 13
using 14

N
network analyzer 38
network cables
category 3 59
category 5 59
category 5e 60
category 6 60
network defined 62

P
package contents 12
panels
front 9
rear 12
password

INDEX

changing 28
default (blank) 28
setting 28
physical features 9
port settings
configuring 31
default settings 32
ports
RJ-45 11
SFP 8, 10
positioning 13
POST 16
powering on 16
power-on self-test See POST
protocol defined 62

R
rack-mounting 14
rear panel
power supply 12
Recovery button 12
resetting to factory defaults 43
RJ-45
defined 62
ports 11

S
server defined 62
SFP ports 8, 10
SFP transceivers 18
approved (supported) 18
inserting 18
removing 19
spot checks 19
subnet mask 62
switch defined 62

T
TCP/IP 61
defined 62
traffic 63

monitoring 38
troubleshooting 43
forgotten IP address 43
forgotten password 43
LED-related issues 44
POST failed 17
trunking See link aggregation

U
user name
default 28

V
viewing
status information 27
VLANs 32
creating 33, 36
maximum supported 33
sample configurations 34

W
Web interface
accessing directly 24
accessing using Discovery 21
buttons 24
connecting 21
logging on 22
menu 23
navigating 23
requirements for accessing 21

REGULATORY NOTICES
FCC STATEMENT
This equipment has been tested and found to comply with the limits for a Class A digital
device, pursuant to part 15 of the FCC rules. These limits are designed to provide
reasonable protection against harmful interference when the equipment is operated in
a commercial environment. This equipment generates, uses and can radiate radio
frequency energy and, if not installed and used in accordance with the instructions, may
cause harmful interference to radio communications. Operation of this equipment in a
residential area is likely to cause harmful interference to radio communications, in which
case the user will be required to correct the interference at their own expense.

INFORMATION TO THE USER
If this equipment does cause interference to radio or television reception, which can be
determined by turning the equipment off and on, the user is encouraged to try to
correct the interference by one or more of the following measures:
■

Reorient the receiving antenna.

■

Relocate the equipment with respect to the receiver.

■

Move the equipment away from the receiver.

■

Plug the equipment into a different outlet so that equipment and receiver are on
different branch circuits.

If necessary, the user should consult the dealer or an experienced radio/television
technician for additional suggestions. The user may find the following booklet prepared
by the Federal Communications Commission helpful:
How to Identify and Resolve Radio-TV Interference Problems
This booklet is available from the U.S. Government Printing Office, Washington,
DC 20402, Stock No. 004-000-00345-4.
In order to meet FCC emissions limits, this equipment must be used only with cables
which comply with IEEE 802.3.

CE STATEMENT (EUROPE)
This product complies with the European Low Voltage Directive 73/23/EEC and EMC
Directive 89/336/EEC as amended by European Directive 93/68/EEC/.

CSA STATEMENT
This Class A digital apparatus meets all requirements of the Canadian
Interference-Causing Equipment Regulations.
Cet appareil numérique de la classe A respecte toutes les exigences du Règlement sur le
matériel brouilleur du Canada.

VCCI STATEMENT

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3Com 2250 Owners Manual 3Com® Baseline Switch Plus (3C16476BS)

2250 to the manual 895764f1-e84f-424d-a6aa-ebf88f3e4ad4

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