3COM 2250 User Manual

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

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CONTENTS

ABOUT THIS GUIDE

Conventions 5
Related Documentation 6
Documentation Comments 6

1 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

2 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 15

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

3 CONNECTING TO THE WEB INTERFACE

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

4 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 39

Upgrading the System Software 40

Configuring the Spanning Tree 41

802.1p Prioritization 41

5 TROUBLESHOOTING

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

A 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 48
Contact Us 48

B 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 54

Stromkabel 54

C TECHNICAL INFORMATION

Related Standards 57

Environmental 57
Physical 57
Electrical 57

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

Ta bl e 1 and Tab le 2 list conventions that are used

throughout this guide.

Tab l e 1 Notice Icons

Icon Notice Type Description

Information
note

Caution Information that alerts you to potential loss of

Warning Information that alerts you to potential

Tab l e 2 Text Conventions

Convention Description

Screen displays

The words “enter”
and “type”

Words in italics Italics are used to:

Information that describes important features
or instructions

data or potential damage to an application,
system, or device

personal injury

This typeface represents information as it
appears on the screen.

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.”

■ 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.

6 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 cur-

rent 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:

[e-mail]

Please include the following information when con­tacting us:

■ Document title

■ Document part number (on the title page)

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.

■ Page number (if appropriate)

Example:

■ 3Com Baseline Switch 2250 Plus User Guide

■ Part number: DUA16476B-SAA01

■ Page 25

1

INTRODUCING THE BASELINE SWITCH

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

®

Baseline Switch 2250 Plus.

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.

8 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.

Tab l e 3 Priority Levels for Traffic Types

Priority Level Traffic Type

0 Best effort

1Background

2 Standard (spare)

3 Excellent effort (business critical)

4 Controlled load (streaming multimedia)

5 Video (interactive media), less than 100

milliseconds latency and jitter

6 Voice (interactive voice), less than 10 milli-

seconds latency and jitter.

7 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 9

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 “
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 “

Panel” on page 12.

Figure 1 Front and Rear Panels

6

Configuring the Spanning Tree”

Front Panel” on page 9 and “Rear

4

1

5

3

2

(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.

7

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.

8

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.

10 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).

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.

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

The following tables describe the LEDs visible on the
front of the Switch, and how to read their status
according to color.

Tab l e 4 10BASE-T/100BASE-TX Ports

Status Meaning

Green Link established, operating at 100 Mbps

Yellow Link established, operating at 10 Mbps

The 1000BASE-T RJ-45 ports support automatic
MDI/MDI-X operation, so you can use
straight-through or crossover cables for all network

Physical Features 11

Status Meaning

Flashing Packets are being received or transmit-

ted on the port

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 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

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.

Tab l e 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 transmit-

ted on the port at 1000 Mbps

Flashing Yellow Packets are being received or transmit-

ted on the port at 10 or 100 Mbps

Status Meaning

Flashing Yellow to

Port disabled or link loopback error

Green

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 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

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

12 CHAPTER 1: INTRODUCING THE BASELINE SWITCH

Off The unit is not receiving power:

■ Verify that the power cord is connected cor-

rectly

■ If the unit still does not operate, contact your

3Com network supplier

Flashing
Green

Yel lo w

■ Power-on self-test is in progress

■ 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.

(8) Recovery Button

Use the Recovery button on the rear panel to reset
the Switch to its factory defaults. For more informa­tion, refer to “

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.

Resetting to Factory Defaults” on

Rear Panel

(7) Power Supply

The Switch automatically adjusts to the supply volt­age. Only use the power cord that is supplied with
the unit.

2

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

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

WARNHINWEIS: Sicherheitsinformationen. Bevor
Sie Komponenten aus dem Switch entfernen oder
dem Switch hinzufuegen oder Instandhaltungsarbe-

of this guide.

(l'Appendice B) de ce guide.

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-

14 CHAPTER 2: INSTALLING THE SWITCH

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

■ The air is as free of dust as possible.

■ Temperature operating limits are not likely to be

exceeded. It is recommended that the unit is
installed in a clean, air conditioned environment.

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.

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

■ Die Luft so frei wie möglich von Staub ist.

■ Es unwahrscheinlich ist das die Betriebstemperatur

überschritten wird. 3Com empfiehlt das Sie den
Switch in einer sauberen, klimatisierten Umgebung
installieren.

Rack-Mounting or Free-Standing

The unit can be mounted in a 19-inch equipment rack
using the supplied mounting kit, (see “

Mounting Kit” on page 14), or it can be free-stand-

ing. 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
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 “

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.

Positioning the Switch” on

Using the

®

3 units,

Rack-Mounting or Free-Standing 15

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

16 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.

To power on the Switch:

1 Plug the power cord into the power socket on the

rear panel of the Switch. Refer to “
on page 12

2 Plug the other end of the power cord into a power

for more information.

(7) Power Supply”

outlet.

When the Switch is powered on, the Power LED lights
up. If the Power LED does not light up, refer to “

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.

Ta bl e 6

summarizes the possible colors for the Power

LED after POST.

Tab l e 6 Possible Power LED Colors After POST

Color State

Green The unit is powered on and ready for use

(5)

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.

Connecting a Network Device 17

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, con-

tact 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.

■ Reset the Switch. See “Resetting to Factory

Defaults” on page 43.

CAUTION: Resetting the Switch to its factory defaults
erases all your settings. You will need to reconfigure
the Switch after you reset it.

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 assis-

tance.

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

Baseline 10/100 switch

Baseline Switch 2250 Plus

1000 Mbps link

10 or 100 Mbps link

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.

Endstations on switched
100 Mbps connections

Endstations on switched
100 Mbps connections

Endstations
on switched
10 or 100 Mbps
connection

1000 Mbps copper
or fiber connection
to backbone or
server/workstation

Server on switched
1000 Mbps
connection

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

18 CHAPTER 2: INSTALLING THE SWITCH

Using SFP Transceivers

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

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.

Approved SFP Transceivers

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

■ 3CSFP91 SFP (SX)

■ 3CSFP92 SFP (LX)

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.

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

If the SFP transceiver is faulty, it will not operate
within the Switch. See “

page 43

.

Troubleshooting” on

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).

Figure 4 Inserting the SFP Transceiver

Product
label

Wire release

lever

Inserting an SFP Transceiver

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

Suitable slot

n host Switcho

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 19

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.

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 Ta bl e 7

Tab l e 7 Items to Check

Item Verify That

Cabling All external cabling connections are secure

Cooling fan Where possible, check that the cooling fan

.

and that no cables are pulled taut

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.

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

20 CHAPTER 2: INSTALLING THE SWITCH

3

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.

The following topics are covered:

■ Requirements for Accessing the Web Interface

■ Running the Discovery Application

■ Logging On to the Web Interface

■ Navigating the Web Interface

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

■ 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.

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

The Welcome screen of Discovery appears.

\Discovery folder on

discovery.exe.

22 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 23

Figure 7 Logon Dialog Box

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.

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.

Figure 8 Switch Screen Layout

Buttons

Menu

Port Status

Ta bl e 8 lists the available items on the menu.

Tab l e 8 Available Menu Items

Menu Item Description

Summary Provides a summary of the Switch’s

Password Allows you to change the administra-

IP Settings Allows you to configure the IP address

basic settings and versions of current
components

tor password

settings of the Switch

24 CHAPTER 3: CONNECTING TO THE WEB INTERFACE

Buttons

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 prioriti-

zation

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

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.

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.

Accessing the Interface Without Using Discovery 25

26 CHAPTER 3: CONNECTING TO THE WEB INTERFACE

4

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

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 inter-

face

■ Assign an IP address to the Switch

■ Configure the Switch’s advanced features

■ Upgrade the firmware

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

.

28 CHAPTER 4: CONFIGURING THE SWITCH

Figure 9 Top Half of the Summary Screen

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

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 29

4 In Confirm Password, retype the password you typed

in step 3 to confirm.

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.

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

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
IP address would be

169.254.1.2. This address is used

08004E000102, the

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

3 The Switch repeats step 2 until an unused IP address

169.254.1.3.

is found.

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

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.

30 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

appears.

Figure 11 IP Settings Screen

2 Configure the Switch’s IP settings. Available options

are listed in Ta bl e 9

.

Tab l e 9 IP Setting Options

Option Description

IP Address Mode 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

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 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 31

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.

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

■ Status – Enables and disables the port

Access Point.

■ 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

■ 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 r u n a
port at 1000Mbps, you must enable autonegotiation
for the port. When autonegotiation is enabled, the

32 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 33

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.

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.

Figure 14 Create VLANs Screen

For examples on setting up VLANs, refer to “

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.

Deleting VLANs

Use the Delete screen to remove a VLAN group from
the current list.

Figure 15 Delete Screen

Sample

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.

34 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.

Figure 16 Modify VLANs Screen

■ Desktop - If you select this, the port can only com-

municate 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.

■ 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

■ VLAN ID – ID of the configured VLAN (1-4094, no

leading zeroes)

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

■ 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 com-

municate with all VLANs on the Switch

■ 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 35

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 2

Port 1

Port 3

Port 26

Server
in VLAN 2

Baseline Switch 2250Baseline Switch 2250 Plus

Server
in VLAN 1

Endstations
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.

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.

3 Click Apply.

36 CHAPTER 4: CONFIGURING THE SWITCH

(

p)

Figure 19 Uplink VLAN Configuration

Endstation
in VLAN 1 (Desktop)

Endstation
in VLAN 2
(Desktop)

Endstation
in VLAN 2
(Desktop)

Endstation
in VLAN 1

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

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

Deskto

Server
in VLAN 1 (Desktop)

Server
in VLAN 2 (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.

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.

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 37

■ All ports in a trunk must be configured in an iden-

tical manner, including communication mode (that
is, speed, duplex mode and flow control).

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 selec-

tion 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.

Figure 21 Membership Screen

■ 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.

38 CHAPTER 4: CONFIGURING THE SWITCH

Figure 22 Summary Screen

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.

To set up traffic monitoring for a port:

1 Connect a network analyzer to a port.

2 Access the Web interface, and then click Tra ffi c 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

which you connected the network analyzer. Traffic to
and from the port selected in Monitor Port will be for-
warded 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 39

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

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

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

■ Click BACKUP to save the current configurations of

the Switch. You will be prompted to download
and save a file to disk.

40 CHAPTER 4: CONFIGURING THE SWITCH

■ To reload configuration settings that you previ-

ously 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.

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 “

ration” 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.

Automatic IP Configu-

Figure 26 Upgrade Screen

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 41

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

42 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.

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.

5 Video (interactive media), less than 100

milliseconds latency and jitter

6 Voice (interactive voice), less than 10 milli-

seconds latency and jitter.

7 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

Tab l e 1 0 Priority Levels for Traffic Types

Priority Level Traffic Type

0 Best effort

1 Background

2 Standard (spare)

3 Excellent effort (business critical)

4 Controlled load (streaming multimedia)

5

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.

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

2 Power off the Switch, and then power it back on,

while keeping the Recovery button pressed.

3 Release the Recovery button.

for illustration.

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
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 “
on page 29

Figure 29 Configuration Tab

for more information.

Forgotten Password

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

) of System Tools. After you

Automatic IP Configuration”

44 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.

For information on using the Discovery application,
refer to “

page 21

Running the Discovery Application” on

.

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 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.

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 cor-

rectly configured.

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

If the Problem Persists 45

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.

■ Product number and serial number (printed on a

label supplied with the unit).

■ A brief description of the issue

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:

46 CHAPTER 5: TROUBLESHOOTING

A

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.

Purchase Value-Added Services

To enhance response times or extend warranty bene­fits, contact 3Com or your authorized 3Com reseller.
Value-added services like 3Com Express

SM

ian

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

SM

and Guard-

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
contains thousands of technical solutions written by
3Com support engineers.

http://knowledgebase.3com.com and

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

First time users will need to apply for a user name and
password. A link to software downloads can be

http://eSupport.3com.com/.

48 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.

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

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

http://eSupport.3com.com/

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
users will need to apply for a user name and pass­word.

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/

http://eSupport.3com.com/. First time

■ A list of system hardware and software, including

revision level

■ Diagnostic error messages

■ Details about recent configuration changes, if

applicable

Contact Us 49

.

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
Ta iw a n
Thailand

You can also obtain support in this region using the following
e-mail: [e-mail]

Or request a repair authorization number (RMA) by fax using
this number: [phone]

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

From anywhere in these
regions, call:

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

1 800 678 515
800 933 486
[phone] or
000800 6501111
001 803 61 009
00531 616 439 or
03 3507 5984
1800 801 777
0800 446 398
[phone]
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

[phone]

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.

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

Country Telephone Number

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

Latin America Telephone Technical Support and
Repair

From the Caribbean, Central and South America, call:

50 APPENDIX A: OBTAINING SUPPORT FOR YOUR PRODUCT

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 [phone]
AT&T [phone]
AT&T [phone]
1 800 998 2112
AT&T [phone]
AT&T [phone]
AT&T [phone]
57 1 657 0888
AT&T [phone]
1 800 998 2112
571 657 0888
01 800 849CARE
AT&T [phone]
AT&T [phone]
54 11 4894 1888
AT&T [phone]
1 800 998 2112
AT&T [phone]
1 800 998 2112
AT&T [phone]
AT&T [phone]
57 1 657 0888

Country Telephone Number

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:

[e-mail]

US and Canada Telephone Technical Support and Repair

1 800 876 3266

B

SAFETY INFORMATION

Important Safety Information

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

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

which it is connected also operates under SELV
conditions.

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).

†

Impédance à la terre

52 APPENDIX B: SAFETY INFORMATION

Power Cord Set

This must be approved for the country where it will
be used.

U.S.A. and Canada ■ The cord set must be UL-approved

Denmark The supply plug must comply with Sec-

Switzerland The supply plug must comply with

UK

Europe

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 cur-

rent 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.

tion 107-2-D1, Standard DK2-1a or
DK2-5a.

SEV/ASE 1011.

■ The supply plug must comply with

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

■ The mains cord must be <HAR> or

<BASEC> marked and be of type
HO3VVF3GO.75 (minimum).

■ The supply plug must comply with

CEE7/7 (“SCHUKO”)

■ The mains cord must be <HAR> or

<BASEC> marked and be of type
HO3VVF3GO.75 (minimum).

WARNING: Fiber Optic Ports – Optical Safety

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

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

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

■ 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.

■ Ne branchez pas votre appareil sur une prise sect-

eur (alimentation électrique) lorsqu'il n'y a pas de
connexion de mise à la terre (mise à la masse).

■ 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.

Consignes Importantes de Sécurité 53

■ 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.

■ 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).

Cordon électrique

Il doit être agréé dans le pays d’utilisation.

Etats-Unis et
Canada:

Danemark: La prise mâle d’alimentation doit respecter la

Suisse: La prise mâle d’alimentation doit respecter la

Europe

■ 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).

section 107-2 D1 de la norme DK2 1a ou
DK2 5a.

norme SEV/ASE 1011.

■ La prise secteur doit être conforme aux

normes CEE 7/7 (“SCHUKO”)

■ LE cordon secteur doit porter la mention

<HAR> ou <BASEC> et doit être de type
HO3VVF3GO.75 (minimum).

54 APPENDIX B: SAFETY INFORMATION

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

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.

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.

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 Wechsel-

stromsteckdose angeschlossen werden.

■ Das Gerät muß an eine geerdete Steckdose ange-

schlossen werden, welche die internationalen
Sicherheitsnormen erfüllt.

■ Der Gerätestecker (der Anschluß an das Gerät,

nicht der Wandsteckdosenstecker) muß einen
gemäß EN 60320/IEC 320 konfigurierten Gerätee­ingang haben.

■ 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.

Stromkabel

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

Schweiz ■ Dieser Stromstecker muß die SEV/ASE

Europe

1011Bestimmungen einhalten.

■ Das Netzkabel muß vom Typ

HO3VVF3GO.75 (Mindestan­forderung) sein und die Aufschrift
<HAR> oder <BASEC> tragen.

■ Der Netzstecker muß die Norm CEE

7/7 erfüllen (”SCHUKO”).

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.

Wichtige Sicherheitshinweise Informationen 55

56 APPENDIX B: SAFETY INFORMATION

C

TECHNICAL INFORMATION

Related Standards

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

Functional ISO 8802-3, IEEE 802.3 (Ethernet),

MAC Address 8192

Safety UL60950-1, EN60950,

EMC Emissions EN 55022 Class A, FCC Part 15

Immunity EN 55024

Environmental

Operating Temperature 0–45 °C (32–113 °F)

Humidity 10–95% (non-condensing)

Standard EN 60068 (IEC 68)—various parts

IEEE 802.3u (Fast Ethernet), IEEE

802.3ab (Gigabit Ethernet), IEEE

802.3x (Flow Control), IEEE 802.1D
1998 (Bridging)

CSA60950-1, IEC60950

Subpart B Class A, ICES-003 Class
A, VCCI Class A, AS/NZS 3548
Class A, CNS 13438 Class A

Physical

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

Electrical

Power Inlet IEC 320

AC Line Frequency 50/60 Hz

Input Voltage 100–240 VAC

Current Rating 2 amperes (maximum)

Maximum Power Con­sumption

Maximum Power Dissi­pation

mounted using the mounting kit
supplied

56 watts

184.3 BTU/hr

58 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.

60 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.

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

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

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.

Ethernet address

See MAC address.

Fast Ethernet

An Ethernet system that is designed to operate at 100
Mbps.

Gigabit Ethernet

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

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.

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 61

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.

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.

IETF

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.

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

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.

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).

Layer 2

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.

link aggregation

See Trunking.

MAC

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.

62 GLOSSARY

network

ping

protocol

RJ-45

server

SFP

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.

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.

A set of rules for communication between devices on
a network. The rules dictate format, timing, sequenc­ing and error control.

A standard connector used to connect Ethernet net­works. The “RJ” stands for “registered jack.”

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.

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.

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).

subnet

A network that is a component of a larger network.

switch

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.

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.

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 63

64 GLOSSARY

INDEX

Numbers

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

A

auto IP configuration 29

default IP address 29

default mask 29
autonegotiation 7
autosensing 7

B

bandwidth 59

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

E

Ethernet 60

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

G

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

L

LAN defined 61
LED issues 44
LEDs

Link/Activity 10
Module Active 11

Power 11
link aggregation 36
local area network 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

66 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

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

T

TCP/IP 61

defined 62
traffic 63

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/.

VCCI STATEMENT

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.