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

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

2015-01-07

: 3Com 3Com-2250-Owners-Manual-135548 3com-2250-owners-manual-135548 3com pdf

Open the PDF directly: View PDF .
Page Count: 67

About This Guide
Introducing the Baseline Switch
Installing the Switch
Connecting to the Web Interface
Configuring the Switch
Troubleshooting
Obtaining Support for Your Product
Safety Information
Technical Information
- Related Standards
Glossary
Index
Regulatory Notices

http://www.3com.com/

Baseline Switch 2250 Plus

(3C16476BS) User Guide

Part No. DUA16476B-SAA02

Published April 2005

3Com Corporation • 350 Campus Drive • Marlborough • MA USA 01752-3064

of this documentation may be reproduced in any form or by any means or

used to make any derivative work (such as translation, transformation, or

adaptation) without written permission from 3Com Corporation.

3Com Corporation reserves the right to revise this documentation and to

make changes in content from time to time without obligation on the part

of 3Com Corporation to provide notification of such revision or change.

3Com Corporation provides this documentation without warranty, term, or

condition of any kind, either implied or expressed, including, but not

limited to, the implied warranties, terms or conditions of merchantability,

satisfactory quality, and fitness for a particular purpose. 3Com may make

improvements or changes in the product(s) and/or the program(s) described

in this documentation at any time.

If there is any software on removable media described in this

documentation, it is furnished under a license agreement included with the

product as a separate document, in the hard copy documentation, or on

the removable media in a directory file named LICENSE.TXT or

!LICENSE.TXT. If you are unable to locate a copy, please contact 3Com and

a copy will be provided to you.

UNITED STATES GOVERNMENT LEGEND

If you are a United States government agency, then this documentation

and the software described herein are provided to you subject to the

following:

All technical data and computer software are commercial in nature and

developed solely at private expense. Software is delivered as “Commercial

Computer Software” as defined in DFARS 252.227-7014 (June 1995) or as

a “commercial item” as defined in FAR 2.101(a) and as such is provided

with only such rights as are provided in 3Com’s standard commercial

license for the Software. Technical data is provided with limited rights only

as provided in DFAR 252.227-7015 (Nov 1995) or FAR 52.227-14 (June

1987), whichever is applicable. You agree not to remove or deface any

portion of any legend provided on any licensed program or documentation

contained in, or delivered to you in conjunction with, this User Guide.

Unless otherwise indicated, 3Com registered trademarks are registered in

the United States and may or may not be registered in other countries.

3Com and the 3Com logo are registered trademarks of 3Com Corporation.

Microsoft, MS-DOS, Windows, and Windows NT are registered trademarks

of Microsoft Corporation.

IEEE and 802 are registered trademarks of the Institute of Electrical and

Electronics Engineers, Inc.

Netscape Navigator is a registered trademark of Netscape Communications.

JavaScript is a trademark of Sun Microsystems.

All other company and product names may be trademarks of the respective

companies with which they are associated.

ENVIRONMENTAL STATEMENT

It is the policy of 3Com Corporation to be environmentally-friendly in all

operations. To uphold our policy, we are committed to:

Establishing environmental performance standards that comply with

national legislation and regulations.

Conserving energy, materials and natural resources in all operations.

Reducing the waste generated by all operations. Ensuring that all waste

conforms to recognized environmental standards. Maximizing the

recyclable and reusable content of all products.

Ensuring that all products can be recycled, reused and disposed of safely.

Ensuring that all products are labelled according to recognized

environmental standards.

Improving our environmental record on a continual basis.

End of Life Statement

3Com processes allow for the recovery, reclamation and safe disposal of all

end-of-life electronic components.

Regulated Materials Statement

3Com products do not contain any hazardous or ozone-depleting material.

Environmental Statement about the Documentation

The documentation for this product is printed on paper that comes from

sustainable, managed forests; it is fully biodegradable and recyclable, and is

completely chlorine-free. The varnish is environmentally-friendly, and the

inks are vegetable-based with a low heavy-metal content.

CONTENTS

ABOUT THIS GUIDE

Conventions 5

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:

pddtechpubs_comments@3com.com

Please include the following information when con-

tacting us:

■Document title

■Document part number (on the title page)

■Page number (if appropriate)

Example:

■3Com Baseline Switch 2250 Plus User Guide

■Part number: DUA16476B-SAA01

■Page 25

Please note that we can only respond to comments

and questions about 3Com product documentation

at this e-mail address. Questions related to technical

support or sales should be directed in the first

instance to your network supplier.

1INTRODUCING THE BASELINE SWITCH

This chapter provides an overview of the features and

capabilities of the 3Com® Baseline Switch 2250 Plus.

It also identifies the contents of the Switch package

and helps you get to know the physical features of

the device.

Overview of the Baseline Switch 2250 Plus

The 3Com® Baseline Switch 2250 Plus is a versatile,

easy-to-use unmanaged switch. It is ideal for users

who want the high-speed performance of 10/100

switching with the added functionality of Gigabit

links but do not need sophisticated management

capabilities.

The Switch is shipped ready for use. No configuration

is necessary, unless you want to configure advanced

features such as VLAN support and link aggregation.

Features and Capabilities

The Switch has 48 shielded RJ-45, 10/100 Mbps

auto-negotiating ports and two 10/100/1000BASE-T

ports that operate in conjunction with two Small

Form Factor Pluggable (SFP) transceiver slots on the

front panel. Use these SFP transceiver slots for easy,

flexible connection to fiber-based Gigabit media.

While there are four physical Gigabit ports, only a

maximum of two can be operational at any given

time.

Autosensing of MDI/MDIX Connections

All ports on the Switch can autosense both medium

dependent interface (MDI) and medium dependent

interface crossover (MDIX) connections. This allows

you to connect network devices to each port using

either a normal straight-through TP (twisted pair)

cable or a ‘crossover’ TP cable.

Any port can therefore be used to connect to another

switch port, server, or workstation without additional

configuration.

Autonegotiating 10/100 Mbps Ports

Each 10/100 Mbps port automatically determines the

speed and duplex mode of the connected equipment

and provides a suitable switched connection. The

1000BASE-T ports also support automatic

10/100/1000 Mbps speed detection.

The 10/100 Mbps connections on these 1000BASE-T

ports operate in full-duplex mode.

8CHAPTER 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 pri-

ority 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 dif-

ferent 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 le 3 Priority Levels for Traffic Types

Forwarding of BPDU Packets

Within an extended local area network that imple-

ments 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-

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

Physical Features 9

able communication paths between switches and to

determine the best available path and block less opti-

mal paths.

For information on configuring BPDU forwarding and

blocking, refer to “Configuring the Spanning Tree”

on page 41.

Physical Features

Figure 1 shows the front and rear panels of the

Switch. The numbers in this diagram refer to num-

bered sections in “Front Panel” on page 9 and “Rear

Panel” on page 12.

Figure 1 Front and Rear Panels

Front Panel

The front panel of the Switch contains a series of indi-

cator lights (LEDs) that help describe the state of vari-

ous networking and connection operations.

(1) 48 RJ-45 Ports

WARNING: RJ-45 Ports. These are shielded RJ-45

data sockets. They cannot be used as standard tradi-

tional 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 conven-

tionnelles standard, ni pour la connection de l’unité à

un réseau téléphonique central privé ou public. Rac-

corder 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 pro-

tégés à ces prises de données.

WARNHINWEIS: RJ-45-Porte. Diese Porte sind

geschützte Datensteckdosen. Sie dürfen weder wie

normale traditionelle Telefonsteckdosen noch für die

Verbindung der Einheit mit einem traditionellem pri-

vatem oder öffentlichem Telefonnetzwerk gebraucht

werden. Nur RJ-45-Datenanscluße, Telefonnetzsys-

teme or Netztelefone an diese Steckdosen

anschließen.

10 CHAPTER 1: INTRODUCING THE BASELINE SWITCH

Entweder geschützte oder ungeschützte Buchsen

dürfen an diese Datensteckdosen angeschlossen wer-

den.

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 deter-

mined by the capabilities of the connected device.

Each port also supports automatic MDI/MDI-X detec-

tion and can be connected to either a 10BASE-T, or a

100BASE-TX device.

CAUTION: The Switch supports full-duplex autone-

gotiation. If the connected device does not support

autonegotiation, the Switch will operate in

half-duplex mode (even if the attached device is oper-

ating 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) trans-

ceiver slots. If an SFP transceiver (purchased sepa-

rately) is installed in a slot and is active, the associated

RJ-45 port of the same number is disabled.

The 1000BASE-T RJ-45 ports support automatic

MDI/MDI-X operation, so you can use

straight-through or crossover cables for all network

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 work-

groups 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 corre-

sponding 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 le 4 10BASE-T/100BASE-TX Ports

Status Meaning

Green Link established, operating at 100 Mbps

Yellow Link established, operating at 10 Mbps

Physical Features 11

Tab le 5 10BASE-T/100BASE-TX/1000BASE-T Ports (4) Module Active LEDs

The Module Active LEDs show the status of any SFP

modules that are installed.

(5) Power LED

The Power LED shows the power status of the Switch.

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 sup-

plier for further advice.

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

Green

Port disabled or link loopback error

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 sup-

plier for further advice.

Status Meaning

Green Fiber SFP is inserted in the slot

Off No fiber SFP is inserted in the slot

Status Meaning

Green The unit is powered on and ready for use

Status Meaning

12 CHAPTER 1: INTRODUCING THE BASELINE SWITCH

(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 under-

side of the unit. Place the unit on top of the lower

unit, ensuring that the pads locate with the recesses

of the lower unit.

Rear Panel

(7) Power Supply

The Switch automatically adjusts to the supply volt-

age. Only use the power cord that is supplied with

the unit.

(8) Recovery Button

Use the Recovery button on the rear panel to reset

the Switch to its factory defaults. For more informa-

tion, refer to “Resetting to Factory Defaults” on

page 43.

Package Contents

The 3Com Baseline Switch 2250 Plus package

includes the following items:

■One 3Com Baseline Switch 2250 Plus unit

■One power cord

■Four standard height, self-adhesive rubber pads

■One mounting kit

■One CD-ROM, which contains this User Guide and

the 3Com Discovery application

■One warranty flyer

Before installing and using the Switch, verify that your

Switch package has all these items. If any of the

above items are damaged or missing, contact your

3Com network supplier immediately.

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

■Power-on self-test is in progress

Yellow ■Power-on self-test or loopback test failed. If

this occurs, reset the Switch to factory

defaults. Refer to “Resetting to Factory

Defaults”

2INSTALLING 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

■Performing Spot Checks

Before You Begin

WARNING: Safety Information. Before installing or

removing any components from the Switch or carry-

ing out any maintenance procedures, read the safety

information provided in Appendix B of this guide.

AVERTISSEMENT: Consignes de sécurité. Avant

d'installer ou d'enlever tout composant du Switch ou

d'entamer une procédure de maintenance, lisez les

informations relatives à la sécurité qui se trouvent

dans Appendix B (l'Appendice B) de ce guide.

WARNHINWEIS: Sicherheitsinformationen. Bevor

Sie Komponenten aus dem Switch entfernen oder

dem Switch hinzufuegen oder Instandhaltungsarbe-

iten verrichten, lesen Sie die Sicherheitsanweisungen,

die in Appendix B (Anhang B) in diesem Handbuch

aufgefuehrt sind.

Positioning the Switch

The Switch is suitable for use in an office environment

where it can be free-standing or mounted in a stan-

dard 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 net-

work.

■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 dis-

charge can cause reliability problems in your equip-

ment.

Aufstellen des Switch

Bei der Entscheidung wo Sie den Switch position-

ieren, 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 Aufzugss-

chächte, Mikrowellen und Klimaanlagen ein. Elek-

tromagnetische 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) Zwischen-

raum 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 “Using the

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® 3 units,

the smaller units must be installed above the larger

ones. Do not have a free-standing stack of more than

six units.

Using the Mounting Kit

The Switch is supplied with two mounting brackets

and four screws. These are used for rack mounting

the unit. When mounting the unit, take note of the

guidelines given in “Positioning the Switch” on

page 13.

The Switch is 1U (1.75 in.) high and will fit in a stan-

dard 19-inch rack.

CAUTION: Before continuing, disconnect all cables

from the unit. Remove the self-adhesive pads from

the underside of unit, if already fitted.

Rack-Mounting or Free-Standing 15

To rack-mount the Switch:

1Place the unit the right way up on a hard, flat surface

with the front facing towards you.

2Locate a mounting bracket over the mounting holes

on one side of the unit.

3Insert the two screws supplied in the mounting kit

and fully tighten with a suitable screwdriver.

Figure 2 Inserting the Screws

4Repeat the two previous steps for the other side of

the unit.

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

suitable screws (not provided). Ensure that the venti-

lation holes are not obstructed.

6Reconnect the network cables.

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 fort-

fahren. Entfernen Sie die selbstklebenden Polster

(Füße) von der Unterseite der Baugruppe, falls diese

bereits angebracht sind.

1Plazieren Sie die Baugruppe aufrecht auf einer harten,

ebenen Fläche mit der Vorderseite zu Ihnen.

2Ordnen Sie eine der Halterungen über den Löchern

an der Seite der Baugruppe an.

3Stecken Sie zwei der mitgelieferten Schrauben in die

Löcher und drehen Sie diese mit einem geeigneten

Schraubendreher fest.

4Widerholen Sie letzten beiden Schritte auf der

anderen Seite der Baugruppe.

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

penträger ein und sichern sie die Baugruppe mit

geeigneten Schrauben. (Nicht im Lieferumfang

enthalten.)

6Schließen 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 cor-

ner. 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 out-

ages. 3Com recommends that you install power con-

ditioning, especially in areas prone to black outs,

power dips and electrical storms.

The unit is intended to be grounded. Ensure it is con-

nected to earth ground during normal use. Installing

proper grounding helps to avoid damage from light-

ning and power surges.

Before powering on the Switch, verify that network

cables and the power cable are securely connected.

CAUTION: The Switch has no ON/OFF switch; the

only method of connecting or disconnecting main

power is by connecting or disconnecting the power

cord.

To power on the Switch:

1Plug the power cord into the power socket on the

rear panel of the Switch. Refer to “(7) Power Supply”

on page 12 for more information.

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

outlet.

When the Switch is powered on, the Power LED lights

up. If the Power LED does not light up, refer to “(5)

Power LED” on page 11 for more information.

Checking for Correct Operation

After you power on the Switch, it automatically per-

forms a power-on self-test (POST). During POST, the

Power LED on the front panel of the Switch flashes

green.

When POST is complete, the Power LED turns green.

If the Power LED turns yellow after POST, it means

that POST failed.

Table 6 summarizes the possible colors for the Power

LED after POST.

Tab le 6 Possible Power LED Colors After POST

Color State

Green The unit is powered on and ready for use

Connecting a Network Device 17

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 success-

fully 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 Cate-

gory 5 unshielded or shielded (screened) 100 Ohm TP

cables (or Category 3 cables for 10 Mbps connec-

tions).

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

To connect a device to the Switch:

1Connect one end of the cable to an RJ-45 port on the

Switch.

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

on the connecting device.

For 1000BASE-T operation, 3Com recommends using

Category 5e or 6 cables.

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

Color State

Baseline 10/100 switch

Endstations on switched

100 Mbps connections

Endstations on switched

100 Mbps connections

Baseline 10/100 switch

Baseline Switch 2250 Plus

1000 Mbps link

10 or 100 Mbps link

Server on switched

1000 Mbps

connection

Endstations

on switched

10 or 100 Mbps

connection

1000 Mbps copper

or fiber connection

to backbone or

server/workstation

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-swappa-

ble. 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 cor-

rect 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.

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

fiber-optic cable or to multimode fiber using a con-

ditioned launch cable.

If the SFP transceiver is faulty, it will not operate

within the Switch. See “Troubleshooting” on

page 43.

To insert an SFP transceiver:

1Hold 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

2Gently 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

Product

label

Suitable slot

n host Switcho

Wire release

lever

Performing Spot Checks 19

not click when you insert it, remove it, turn it over,

and then re-insert it.

3Remove the plastic protective cover, if fitted.

4Connect the fiber cable.

5The transceiver connects to the network using a

duplex LC connector. Attach a male duplex LC con-

nector on the network cable into the duplex LC con-

nector on the transceiver.

6Connect the other end of the cable to a device fitted

with an appropriate Gigabit Ethernet connection.

7Check 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 power-

ing off the Switch.

To remove an SFP transceiver:

1Disconnect the cable from the transceiver.

2Move the wire release lever downwards until it is

pointing toward you.

3Pull the wire release lever toward you to release the

catch mechanism.

The SFP transceiver should slide out easily.

Performing Spot Checks

At frequent intervals, you should visually check the

Switch. Regular checks can give you an early warning

of a possible failure; any problems can then be

attended to when there will be least effect on users.

3Com recommends periodically checking the items

listed in Table 7.

Tab le 7 Items to Check

If you experience any problems operating the Switch,

refer to “Troubleshooting” starting on page 43.

Item Verify That

Cabling All external cabling connections are secure

and that no cables are pulled taut

Cooling fan Where possible, check that the cooling fan

is operating by listening to the unit. The

fan is fitted near to the front right hand

side of the unit (when viewed from the

front).

20 CHAPTER 2: INSTALLING THE SWITCH

3CONNECTING 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 appli-

cation. 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 fol-

lowing:

■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 con-

tains, among others, the Discovery application.

To use Discovery to connect to the Web interface, do

the following:

1On 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 \Discovery folder on

the CD-ROM, and then double-click discovery.exe.

The Welcome screen of Discovery appears.

22 CHAPTER 3: CONNECTING TO THE WEB INTERFACE

Figure 5 Welcome Screen of Discovery

2If 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

3On the Discovered Devices screen, click Baseline

Switch 2250 Plus, and then click Next.

The Completing the 3Com Discovery Application

screen appears.

4Click 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:

1In User name, type admin.

2Leave the Password field blank.

3Click 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.

The menu is located on the left side of the Web inter-

face. When you click an item on the menu, the

related screen appears in the main part of the inter-

face.

Figure 8 Switch Screen Layout

Table 8 lists the available items on the menu.

Tab le 8 Available Menu Items

Menu Item Description

Summary Provides a summary of the Switch’s

basic settings and versions of current

components

Password Allows you to change the administra-

tor password

IP Settings Allows you to configure the IP address

settings of the Switch

Buttons

Port Status

24 CHAPTER 3: CONNECTING TO THE WEB INTERFACE

Buttons

Depending on the screen that is currently displayed,

the following buttons may appear:

■Apply – Click to save and apply any changes that

you have made

■Cancel – Click to discard any unsaved changes

■Help – Click to display the context-sensitive help

information for the screen that is currently dis-

played. 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 Dis-

covery.

This section describes how to access the interface

directly, without using Discovery.

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

Menu Item Description

Accessing the Interface Without Using Discovery 25

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 inter-

face 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.

26 CHAPTER 3: CONNECTING TO THE WEB INTERFACE

4CONFIGURING THE SWITCH

This chapter provides information on how to config-

ure 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 config-

ure 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 hard-

ware (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 informa-

tion on this screen.

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)

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 pass-

word to prevent unauthorized access to your net-

work.

Figure 10 Change Administration Password Screen

To set the admin password:

1On the menu, click Password. The Change Adminis-

tration Password screen appears.

2In 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.

3In New Password, type the password that you want to

set.

Modifying the IP Address Settings 29

4In Confirm Password, retype the password you typed

in step 3 to confirm.

The password is case-sensitive.

5Click 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 configu-

ration and assigns an IP address to itself. This is neces-

sary for the Discovery application to be able to

connect to the Web interface.

Automatic IP Configuration

When you power on the Switch for the first time, it

automatically uses the default IP address

169.254.x.y, where x and y are the last two bytes of

its MAC address.

To determine the exact IP address that the Switch

assigns to itself during auto IP configuration, check

the sticker on the base of the Switch. This sticker con-

tains the MAC address and default IP address of the

Switch.

To detect its IP information using the automatic con-

figuration process, the Switch goes through the fol-

lowing sequence of steps:

1The Switch tries to configure itself with the default IP

address 169.254.x.y, where x and y are converted

from the last two bytes of its MAC address.

For example, if the MAC address is 08004E000102, the

IP address would be 169.254.1.2. This address is used

if the Switch is operating in a standalone mode, or no

other switches on the network have this IP address.

The Switch also assigns the subnet mask 255.255.0.0

(default class B mask) to itself.

2If this default IP address is already in use on the net-

work, then the Switch detects this, and increments

the last byte of the MAC address by one to generate

its IP address.

The IP address would therefore become 169.254.1.3.

3The Switch repeats step 2 until an unused IP address

is found.

3Com recommends using automatic IP configuration

only for the initial setup. Once you gain access to the

console, you should assign an IP address to the Switch

(either by using DHCP or assigning a static IP address)

to ensure successful communication between the

Switch and other network devices.

30 CHAPTER 4: CONFIGURING THE SWITCH

Setting the IP Address

To set the IP address for the Switch:

1Click IP Settings on the menu. The IP Settings screen

appears.

Figure 11 IP Settings Screen

2Configure the Switch’s IP settings. Available options

are listed in Tab l e 9.

Tab le 9 IP Setting Options

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

click Apply to save your changes.

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 man-

agement stations on other network seg-

ments. 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

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 Access Point.

■Status – Enables and disables the port

■Flow Control – Enables and disables flow control

on the port. When flow control is enabled for the

port, the Switch regulates the packet flow so that

a sending device does not transmit more packets

than a receiving device can process. If flow control

is disabled, packets may be dropped under certain

periods of high traffic.

Flow control is enabled by default.

■Speed Duplex – 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

Speed/Duplex for 1000 Mbps Connections

You cannot preset the speed to 1000Mbps. To run a

port at 1000Mbps, you must enable autonegotiation

for the port. When autonegotiation is enabled, the

32 CHAPTER 4: CONFIGURING THE SWITCH

Switch will automatically connect at 1000Mbps, pro-

viding 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 set-

ting, 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 pro-

cess over again. Broadcast storms use substantial net-

work 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 communi-

cate 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

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)

For examples on setting up VLANs, refer to “Sample

VLAN Configurations”.

CAUTION: At least one port must always be a

member of VLAN 1 (the management VLAN). If you

choose to connect all ports to VLANs other than

VLAN 1, you will no longer be able to access the Web

interface. If this happens, you will need to reset the

Switch to factory settings.

By default, all ports belong to VLAN 1.

Deleting VLANs

Use the Delete screen to remove a VLAN group from

the current list.

Figure 15 Delete Screen

■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 com-

municate with all other VLANs, or a selected VLAN.

Figure 16 Modify VLANs Screen

■Port – Displays the port number

■Mode – The mode option determines if the port

can communicate with all VLANs, or only with a

selected VLAN

■Uplink – If you select this, the port is able to com-

municate with all VLANs on the Switch

■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 mem-

bers 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)

■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

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:

1Create 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.

2Set ports 1, 3, and 26 to Desktop mode.

3Click Apply.

Ports 1, 3, and 26 now belong to VLAN2, and will not

communicate with any other ports, unless you add

other ports to the VLAN or change the port configu-

ration.

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, pro-

vided that a port on each Switch is set to uplink, and

that these ports are connected.

Baseline Switch 2250Baseline Switch 2250 Plus

Server

in VLAN 1

Endstations

in VLAN 1

Endstations

in VLAN 2

Server

in VLAN 2

Port 1

Port 3

Port 26

36 CHAPTER 4: CONFIGURING THE SWITCH

Figure 19 Uplink VLAN Configuration

To set up the configuration shown in Figure 19, do

the following:

1Create 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.

2On 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.

3On 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.

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

port 16) to the uplink port on Switch 2 (in this exam-

ple, 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 effec-

tively combine the bandwidth into a single connec-

tion 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 con-

figured 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.

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

Endstation

in VLAN 2

(Desktop)

Endstation

in VLAN 1 (Desktop) Server

in VLAN 1 (Desktop)

Endstation

in VLAN 2

(Desktop)

Endstation

in VLAN 1

(

Deskto

Server

in VLAN 2 (Desktop)

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

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 dis-

abled, 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 under-

Trunking.

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 analy-

sis 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 moni-

toring, 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:

1Connect a network analyzer to a port.

2Access the Web interface, and then click Traffic Mon-

itoring on the menu. The Port Traffic Monitoring

Screen appears.

3On the Monitor Port menu, select the port number

that you want to monitor.

4On 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.

5In 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.

6Click Apply.

Using the System Tools 39

For information on how to interpret the output on

the port analyzer, refer to its accompanying docu-

mentation.

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 Configura-

tion 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 configu-

ration 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 “Automatic IP Configu-

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.

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 run-

ning 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 soft-

ware 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 span-

ning 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 predeter-

mined 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 for-

wards 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 for-

ward BPDUs to other ports.

The Switch does not participate as a bridge node in

the spanning tree, it can only be configured to for-

ward 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 con-

nected 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 prior-

ity 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 dif-

ferent 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 le 10 Priority Levels for Traffic Types

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 ser-

vices each priority queue. The Switch allows you to

choose between using IP Precedence or DSCP (Differ-

entiated 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

Priority Level Traffic Type

0 Best effort

1 Background

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

5TROUBLESHOOTING

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 firm-

ware 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:

1Using the tip of a pen (or a similar object), press the

Recovery button on the rear panel of the Switch. See

Figure 1 for illustration.

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

while keeping the Recovery button pressed.

3Release the Recovery button.

4Reset the Switch either by:

■Accessing the Web interface using Discovery, and

then pressing the RESET button on the Configura-

tion tab (see Figure 29) of System Tools. After you

click RESET, a confirmation message appears. Click

OK to confirm.

■Powering off the Switch, and then powering it

back on.

The Switch will perform automatic IP configuration

after you reset it. See “Automatic IP Configuration”

on page 29 for more information.

Figure 29 Configuration Tab

Forgotten Password

If you forget the password to the Web interface after

you set it, you will need to reset the Switch to regain

44 CHAPTER 5: TROUBLESHOOTING

access. See “Resetting to Factory Defaults” on

page 43 for instructions.

After resetting the Switch, log on to the Web inter-

face 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 “Running the Discovery Application” on

page 21.

Solving LED Issues

This section lists some issues that are related to the

LEDs on the front panel of the Switch. For informa-

tion on basic LED checks, refer to the following topics

in Chapter 1:

■(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 perfor-

mance is poor

If the Problem Persists 45

The Switch supports full-duplex autonegotiation. If

the connected device does not support autonegotia-

tion, ensure that it is configured for half-duplex oper-

ation only. If the connected device has

autonegotiation disabled or overridden, and is config-

ured as full-duplex, the Switch will configure the link

as half-duplex, causing a mismatch that will reduce

network performance when data is transmitting and

receiving simultaneously on the same link.

Ensure that the connected device has either:

■Autonegotiation enabled, or

■The ports are configured for half-duplex operation

All ports appear to show continual activity.

There may be broadcast storms on the network.

Remove port connections one at a time, waiting a

few seconds between each port. If the LEDs go off

after removing a port connection, the device that was

connected to that port is introducing an excessive

amount of broadcast frames to the network. Some

pieces of network equipment operate by sending out

broadcast frames regularly.

Refer to the documentation that accompanies the

device for information on disabling the broadcast

operation.

If the Problem Persists

If the problem persists and the unit still does not

operate successfully, contact your 3Com network

supplier with the following information before return-

ing the unit:

■Product number and serial number (printed on a

label supplied with the unit).

■A brief description of the issue

46 CHAPTER 5: TROUBLESHOOTING

AOBTAINING SUPPORT FOR 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 war-

ranty 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 bene-

fits, contact 3Com or your authorized 3Com reseller.

Value-added services like 3Com ExpressSM and Guard-

ianSM 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

projects. More information on 3Com maintenance

and Professional Services is available at

http://www.3com.com/

Contact your authorized 3Com reseller or 3Com for a

complete list of the value-added services available in

your area.

Troubleshoot Online

You will find support tools posted on the 3Com web

site at http://www.3com.com/

3Com Knowledgebase helps you troubleshoot

3Com products. This query-based interactive tool is

located at http://knowledgebase.3com.com and

contains thousands of technical solutions written by

3Com support engineers.

Access Software Downloads

Software Updates are the bug fix / maintenance

releases for the version of software initially purchased

with the product. In order to access these Software

Updates you must first register your product on the

3Com web site at http://eSupport.3com.com/.

First time users will need to apply for a user name and

password. A link to software downloads can be

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 origi-

nal product. In order to access upgrades and related

documentation you must first purchase a service con-

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

Warranty and other service benefits start from the

date of purchase, so it is important to register your

product quickly to ensure you get full use of the war-

ranty and other service benefits available to you.

When you contact 3Com for assistance, please have

the following information ready:

■Product model name, part number, and serial

number

■Proof of purchase, if you have not pre-registered

your product

■A list of system hardware and software, including

revision level

■Diagnostic error messages

■Details about recent configuration changes, if

applicable

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 pack-

age, will be returned to the sender unopened, at the

sender’s expense. If your product is registered and

under warranty, you can obtain an RMA number

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

users will need to apply for a user name and pass-

word.

3Com offers telephone, e-mail and internet access to

technical support and repair services. To access these

services for your region, use the appropriate tele-

phone number, URL or e-mail address from the list

below.

Telephone numbers are correct at the time of publica-

tion. Find a current directory of support telephone

numbers posted on the 3Com web site at

http://csoweb4.3com.com/contactus/

Country Telephone Number

Asia, Pacific Rim Telephone Technical Support and

Repair

Australia

Hong Kong

India

Indonesia

Japan

Malaysia

New Zealand

Pakistan

Philippines

P.R. of China

Singapore

S. Korea

Taiwan

Thailand

1 800 678 515

800 933 486

+61 2 9424 5179 or

000800 6501111

001 803 61 009

00531 616 439 or

03 3507 5984

1800 801 777

0800 446 398

+61 2 9937 5083

1235 61 266 2602 or

1800 1 888 9469

800 810 3033

800 6161 463

080 333 3308

00801 611 261

001 800 611 2000

You can also obtain support in this region using the following

e-mail: apr_technical_support@3com.com

Or request a repair authorization number (RMA) by fax using

this number: +65 543 6348

Europe, Middle East, and Africa Telephone Technical

Support and Repair

From anywhere in these

regions, call:

+44 (0)1442 435529

From the following countries, you may use the numbers

shown:

Austria

Belgium

Denmark

Finland

France

Germany

Hungary

Ireland

Israel

Italy

Luxembourg

Netherlands

Norway

Poland

Portugal

South Africa

Spain

Sweden

Switzerland

U.K.

01 7956 7124

070 700 770

7010 7289

01080 2783

0825 809 622

01805 404 747

06800 12813

1407 3387

1800 945 3794

199 161346

342 0808128

0900 777 7737

815 33 047

00800 441 1357

707 200 123

0800 995 014

9 021 60455

07711 14453

08488 50112

0870 909 3266

You can also obtain support in this region using the following

URL: http://emea.3com.com/support/email.html

Country Telephone Number

Latin America Telephone Technical Support and

Repair

From the Caribbean, Central and South America, call:

Country Telephone Number

50 APPENDIX A: OBTAINING SUPPORT FOR YOUR PRODUCT

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

52 5 201 0010

1 800 998 2112

0800 13 3COM

1 800 998 2112

AT&T +800 998 2112

1 800 998 2112

AT&T +800 998 2112

57 1 657 0888

AT&T +800 998 2112

1 800 998 2112

571 657 0888

01 800 849CARE

AT&T +800 998 2112

54 11 4894 1888

AT&T +800 998 2112

1 800 998 2112

AT&T +800 998 2112

1 800 998 2112

AT&T +800 998 2112

57 1 657 0888

Country Telephone Number

You can also obtain support in this region using the follow-

ing:

Spanish speakers, enter the URL:

http://lat.3com.com/lat/support/form.html

Portuguese speakers, enter the URL:

http://lat.3com.com/br/support/form.html

English speakers in Latin America should send e-mail to:

lat_support_anc@3com.com

US and Canada Telephone Technical Support and Repair

1 800 876 3266

Country Telephone Number

BSAFETY 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 con-

ditions 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.

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 perfor-

mance 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 suiva-

nte 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 config-

uration qui permet un branchement sur une entrée

d’appareil EN60320/IEC 320.

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

and CSA certified.

■The minimum specifications for the

flexible cord are:

No. 18 AWG

Type SV or SJ

3-conductor

■The cord set must have a rated 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.

Denmark The supply plug must comply with Sec-

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

DK2-5a.

Switzerland The supply plug must comply with

SEV/ASE 1011.

UK ■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).

Europe ■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).

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 débran-

chant 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 ali-

menté 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’appella-

tion Neutre et avec raccordement direct à la terre

(masse).

Cordon électrique

Il doit être agréé dans le pays d’utilisation.

Etats-Unis et

Canada:

■Le cordon doit avoir reçu l’homologation

des UL et un certificat de la CSA.

■Le cordon souple doit respecter, à titre

minimum, les spécifications suivantes:

calibre 18 AWG

type SV ou SJ

à 3 conducteurs

■Le cordon doit être en mesure d’acheminer

un courant nominal d’au moins 10 A.

■La prise femelle de branchement doit être

du type à mise à la terre (mise à la masse)

et respecter la configuration NEMA 5-15P

(15 A, 125 V) ou NEMA 6-15P (15 A, 250

V).

Danemark: La prise mâle d’alimentation doit respecter la

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

DK2 5a.

Suisse: La prise mâle d’alimentation doit respecter la

norme SEV/ASE 1011.

Europe ■La prise secteur doit être conforme aux

normes CEE 7/7 (“SCHUKO”)

■LE cordon secteur doit porter la mention

<HAR> ou <BASEC> et doit être de type

HO3VVF3GO.75 (minimum).

54 APPENDIX B: SAFETY INFORMATION

AVERTISSEMENT: Ports pour fibres optiques – sécu-

rité 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 docu-

ment risquent d'entraîner l'exposition à des rayonne-

ments laser dangereux.

Wichtige Sicherheitshinweise Informationen

Bitte unbedingt vor dem Einbauen des Baseline

Switch 2250 Plus die folgenden Sicherheitsanweisun-

gen 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 Gerätee-

ingang 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 unterbro-

chen 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 angeschlos-

senen 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

1011Bestimmungen einhalten.

Europe ■Das Netzkabel muß vom Typ

HO3VVF3GO.75 (Mindestan-

forderung) sein und die Aufschrift

<HAR> oder <BASEC> tragen.

■Der Netzstecker muß die Norm CEE

7/7 erfüllen (”SCHUKO”).

Wichtige Sicherheitshinweise Informationen 55

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 Faser-

ansnchlüsse 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.

56 APPENDIX B: SAFETY INFORMATION

CTECHNICAL INFORMATION

Related Standards

The 3Com Baseline Switch 2250 Plus has been

designed to the following standards:

Environmental

Physical

Electrical

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

IEEE 802.3u (Fast Ethernet), IEEE

802.3ab (Gigabit Ethernet), IEEE

802.3x (Flow Control), IEEE 802.1D

1998 (Bridging)

MAC Address 8192

Safety UL60950-1, EN60950,

CSA60950-1, IEC60950

EMC Emissions EN 55022 Class A, FCC Part 15

Subpart B Class A, ICES-003 Class

A, VCCI Class A, AS/NZS 3548

Class A, CNS 13438 Class A

Immunity EN 55024

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

Humidity 10–95% (non-condensing)

Standard EN 60068 (IEC 68)—various parts

Width 440 mm (17.3 in.)

Depth 235.5 mm (9.2 in.)

Height 43.6 mm (1.7 in.) or 1U

Weight 3.1 kgs (6.83 lbs)

Mounting Free standing, or 19 in. rack

mounted using the mounting kit

supplied

Power Inlet IEC 320

AC Line Frequency 50/60 Hz

Input Voltage 100–240 VAC

Current Rating 2 amperes (maximum)

Maximum Power Con-

sumption

56 watts

Maximum Power Dissi-

pation

184.3 BTU/hr

58 APPENDIX C: TECHNICAL INFORMATION

GLOSSARY

10BASE-T

The IEEE specification for 10 Mbps Ethernet over Cat-

egory 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 multi-

mode 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 opera-

tion that takes place in a few milliseconds. Autonego-

tiation must be enabled for the 1000BASE-T ports to

operate at 1000 Mbps, full-duplex.

bandwidth

The information capacity (measured in bits per sec-

ond) 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 net-

works (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 con-

nected to your network.

DHCP

Dynamic Host Configuration Protocol. This protocol

automatically assigns an IP address for every com-

puter 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 net-

works 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 pri-

ority 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.

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 net-

work 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 peri-

ods (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 Communica-

tions Protocol. This is related directly to the hardware

interface for the network devices and passes on traf-

fic 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 hard-

ware, 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

A network is a collection of computers and other

computer equipment that are connected for the pur-

pose of exchanging information or sharing resources.

Networks vary in size, some are within a single room,

others span continents.

ping

Packet Internet Groper. An internet utility used to

determine whether a particular IP address is online. It

is used to test and debug a network by sending out a

packet and waiting for a response.

protocol

A set of rules for communication between devices on

a network. The rules dictate format, timing, sequenc-

ing and error control.

RJ-45

A standard connector used to connect Ethernet net-

works. The “RJ” stands for “registered jack.”

server

A computer on a network that is shared by multiple

end stations. Servers provide end stations with access

to shared network services such as computer files and

printer queues.

SFP

Small Form Factor Pluggable (SFP) Connectors are

based on an open standard that enables hot swap-

ping 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 particu-

lar 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 seg-

ments. Switches are similar to bridges, in that they

connect LANs of a different type; however they con-

nect 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. Origi-

nally a UNIX standard, TCP/IP is now supported on

almost all platforms, and is the protocol of the Inter-

net.

GLOSSARY 63

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 destina-

tion. 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 mon-

itor 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 barri-

ers, and allows users to share information and

resources as though located on the same LAN.

64 GLOSSARY

INDEX

Numbers

1000BASE-LX 59

1000BASE-SX 59

1000BASE-T 59

100BASE-TX 59

10BASE-T 59

auto IP configuration 29

default IP address 29

default mask 29

autonegotiation 7

autosensing 7

bandwidth 59

client 60

configuration

overview 27

connecting

network device 17

SFP transceivers 18

conventions

notice icons, About This Guide 5

text, About This Guide 5

DHCP 60

Discovery 21

dynamic host control protocol See DHCP

Ethernet 60

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

Gigabit Ethernet 60

half-duplex 60

IEEE 60

IETF 61

installing 13

IP address

auto configuration 29

modifying 29

setting 30

IP defined 61

LAN defined 61

LED issues 44

LEDs

Link/Activity 10

Module Active 11

Power 11

link aggregation 36

local area network 61

MAC address 61

media access control 61

monitoring traffic 38

mounting kit

contents 13

using 14

network analyzer 38

network cables

category 3 59

category 5 59

category 5e 60

category 6 60

network defined 62

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

rack-mounting 14

rear panel

power supply 12

Recovery button 12

resetting to factory defaults 43

RJ-45

defined 62

ports 11

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

TCP/IP 61

defined 62

traffic 63

monitoring 38

troubleshooting 43

forgotten IP address 43

forgotten password 43

LED-related issues 44

POST failed 17

trunking See link aggregation

user name

default 28

viewing

status information 27

VLANs 32

creating 33, 36

maximum supported 33

sample configurations 34

Web interface

accessing directly 24

accessing using Discovery 21

buttons 24

connecting 21

logging on 22

menu 23

navigating 23

requirements for accessing 21

REGULATORY NOTICES

FCC STATEMENT

This equipment has been tested and found to comply with the limits for a Class A digital

device, pursuant to part 15 of the FCC rules. These limits are designed to provide

reasonable protection against harmful interference when the equipment is operated in

a commercial environment. This equipment generates, uses and can radiate radio

frequency energy and, if not installed and used in accordance with the instructions, may

cause harmful interference to radio communications. Operation of this equipment in a

residential area is likely to cause harmful interference to radio communications, in which

case the user will be required to correct the interference at their own expense.

INFORMATION TO THE USER

If this equipment does cause interference to radio or television reception, which can be

determined by turning the equipment off and on, the user is encouraged to try to

correct the interference by one or more of the following measures:

■Reorient the receiving antenna.

■Relocate the equipment with respect to the receiver.

■Move the equipment away from the receiver.

■Plug the equipment into a different outlet so that equipment and receiver are on

different branch circuits.

If necessary, the user should consult the dealer or an experienced radio/television

technician for additional suggestions. The user may find the following booklet prepared

by the Federal Communications Commission helpful:

How to Identify and Resolve Radio-TV Interference Problems

This booklet is available from the U.S. Government Printing Office, Washington,

DC 20402, Stock No. 004-000-00345-4.

In order to meet FCC emissions limits, this equipment must be used only with cables

which comply with IEEE 802.3.

CE STATEMENT (EUROPE)

This product complies with the European Low Voltage Directive 73/23/EEC and EMC

Directive 89/336/EEC as amended by European Directive 93/68/EEC/.

CSA STATEMENT

This Class A digital apparatus meets all requirements of the Canadian

Interference-Causing Equipment Regulations.

Cet appareil numérique de la classe A respecte toutes les exigences du Règlement sur le

matériel brouilleur du Canada.

VCCI STATEMENT

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

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

Navigation menu

Versions of this User Manual:

Views

Navigation