D-Link DES-3250TG User manual

DES-3250TG
Standalone Layer 2 Switch
User’s Guide
Second Edition (July 2003)
651TG3250035
Printed In Taiwan
RECYCLABLE

D-Link Offices for Registration and Warranty Service
The product's Registration Card, provided at the back of this manual, must be
sent to a D-Link office. To obtain an RMA number for warranty service as to a
hardware product, or to obtain warranty service as to a software product,
contact the D-Link office nearest you. An address/telephone/fax/e-mail/Web
site list of D-Link offices is provided in the back of this manual.
Trademarks
Copyright 2003 D-Link Corporation.
Contents subject to change without prior notice.
D-Link is a registered trademark of D-Link Corporation/D-Link
Systems, Inc. All other trademarks belong to their respective
proprietors.
Copyright Statement
No part of this publication may be reproduced in any form or by any
means or used to make any derivative such as translation,
transformation, or adaptation without permission from D-Link
Corporation/D-Link Systems Inc., as stipulated by the United States
Copyright Act of 1976.
FCC Warning
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
this user’s guide, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is
likely to cause harmful interference in which case the user will be
required to correct the interference at his own expense.
CE Mark Warning
This is a Class A product. In a domestic environment, this product
may cause radio interference in which case the user may be required
to take adequate measures.

VCCI Warning

v
Table of Contents
Introduction............................................................................1
Features ...............................................................................1
Ports ..................................................................................1
Performance Features...........................................................2
Traffic Classification and Prioritization ............................... 3
Management ......................................................................4
Fast Ethernet Technology .....................................................5
Gigabit Ethernet Technology.................................................5
Unpacking and Setup..............................................................6
Unpacking ............................................................................6
Installation ...........................................................................7
Desktop or Shelf Installation ..............................................7
Rack Installation................................................................8
Power on...............................................................................9
Power Failure ................................................................... 10
Identifying External Components ..........................................11
Front Panel.........................................................................11
Rear Panel ..........................................................................12
Side Panels.........................................................................13
Gigabit Combo Ports...........................................................13
LED Indicators ...................................................................14
Connecting The Switch..........................................................16
Switch to End Node ............................................................16
Switch to Hub or Switch .....................................................17
10BASE-T Device .............................................................18
100BASE-TX Device.........................................................18
Switch Management and Operating Concepts .......................19
Local Console Management ................................................19
Diagnostic (console) port (RS-232 DCE)............................20

vi
Switch IP Address...............................................................21
SNMP .................................................................................23
MIBs...................................................................................25
Packet Forwarding..............................................................26
802.1w Rapid Spanning Tree ..............................................27
Link Aggregation.................................................................30
VLANs ................................................................................32
IP Addresses .......................................................................40
Internet Protocols ...............................................................47
Packet Headers...................................................................54
Web-Based Switch Management............................................63
Introduction .......................................................................63
Before You Start .................................................................64
Getting Started ...................................................................64
Configuring the Switch .......................................................65
User Accounts Management.............................................65
Save Changes...................................................................67
Using Web-Based Management...........................................69
Configuration .....................................................................74
IP Address........................................................................74
Switch Information...........................................................78
Advanced Settings............................................................79
Port Configuration............................................................81
Port Mirroring ..................................................................84
Link Aggregation ..............................................................86
IGMP................................................................................89
Spanning Tree..................................................................94
Forwarding Filtering.......................................................102
VLANs............................................................................105
Port Bandwidth .............................................................. 112
SNTP Settings ................................................................ 114
Port Security .................................................................. 118
QOS (Quality of Service) .................................................121
Access Profile Table........................................................ 130
PAE Access Entity .......................................................... 138
Management..................................................................... 150
Security IP ..................................................................... 150

vii
User Accounts................................................................152
SNMPV3.........................................................................153
Monitoring........................................................................166
Port Utilization ...............................................................166
Packets .......................................................................... 168
Errors ............................................................................176
Size ................................................................................ 182
MAC Address .................................................................186
IGMP Snooping Group ...................................................188
IGMP Snooping Forwarding............................................190
VLAN Status ..................................................................191
Router Port ....................................................................191
Port Access Control ........................................................ 192
Maintenance..................................................................... 193
TFTP Utilities .................................................................193
Switch History................................................................196
Ping Test ........................................................................ 197
Save Changes................................................................. 197
Reboot Services.............................................................. 198
Logout............................................................................ 200
Warranty and Registration ..................................................201
All countries and regions except USA .............................201
USA Only .......................................................................204
Technical Specifications ...................................................... 208
Understanding and Troubleshooting the Spanning Tree
Protocol............................................................................... 211
Brief Review of Bitwise Logical Operations...........................227
Index................................................................................... 229

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
1
1
INTRODUCTION
This section describes the functionality features of the
DES-3250TG.
Features
The DES-3250TG Switch was designed for easy installation
and high performance in an environment where traffic on the
network and the number of users increase continuously.
Switch features include:
Ports
• Forty-eight high-performance NWay ports all operating
at 10/100 Mbps for connecting to end stations, servers
and hubs.
• All 48 10/100 UTP ports can auto-negotiate (NWay)
between 10Mbps/100Mbps, half-duplex or full duplex.
• One front panel slide-in module interface for a 2-port
1000BASE-T module (provided) and one front panel
slide-in module interface for a 2-port Mini GBIC Gigabit

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
2
Ethernet module (optional). Please note that although
these two front panel modules can be used
simultaneously, the ports must be different. For
example, if port 49x is used on the Mini GBIC module,
port 49x is not available on the 1000BASE-T module,
and vice versa.
• RS-232 DCE Diagnostic port (console port) for setting up
and managing the Switch via a connection to a console
terminal or PC using a terminal emulation program.
Performance Features
• Store and forward switching scheme.
• Full and half-duplex for both 10Mbps and 100Mbps
connections. The front-port Gigabit Ethernet module
operates at full duplex only. Full duplex allows the
switch port to simultaneously transmit and receive data,
and only works with connections to full-duplex capable
end stations and switches. Connections to hubs must
take place at half-duplex.
• Auto-polarity detection and correction of incorrect
polarity on the transmit and receive twisted-pair at each
port.
• IEEE 802.3z compliant for Mini GBIC ports (optional
module).
• IEEE 802.3ab compliant for 1000BASE-T (Copper)
Gigabit ports (optional module).
• Data forwarding rate 14,880 pps per port at 100% of
wire-speed for 10Mbps speed.

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
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• Data forwarding rate 148,800 pps per port at 100% of
wire-speed for 100Mbps speed.
• Data filtering rate eliminates all error packets, runts,
etc. at 14,880 pps per port at 100% of wire-speed for
10Mbps speed.
• Data filtering rate eliminates all error packets, runts,
etc. at 148,800 pps per port at 100% of wire-speed for
100Mbps speed.
• 8K active MAC address entry table per device with
automatic learning and aging (10 to 1,000,000 seconds).
• 64 MB packet buffer per device.
• Supports Port Mirroring.
• Supports Port Trunking.
• 802.1D Spanning Tree support.
• 802.1Q Tagged VLAN support – up to 255 VLANs per
device (one VLAN is reserved for internal use).
• GVRP – (GARP VLAN Registration Protocol) support for
dynamic VLAN registration.
• 802.1p Priority support with 4 priority queues.
• IGMP Snooping support.
Traffic Classification and Prioritization
• Based on 802.1p priority bits.
• Four priority queues.

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
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Management
• RS-232 console port for out-of-band network
management via a console terminal or PC.
• Fast Spanning Tree Algorithm Protocol for creation of
alternative backup paths and prevention of network
loops.
• SNMP V1, V2C, and V3 are supported.
• Fully configurable in-band control for SNMP based
software.
• Flash memory for software upgrades. This can be done
in-band via TFTP or out-of-band via the console.
• Built-in SNMP management:
 SNMP V2-MIB (RFC 1907).
 Bridge MIB (RFC 1493).
 MIB-II (RFC 1213).
 IF MIB (RFC 2233).
 Entity MIB (RFC 2737).
 RMON MIB (RFC 1757) – 4 groups. The RMON
specification defines the Counters for the Receive
function only. However, the DES-3250TG
implements counters for both receive and
transmit functions.
 802.1p MIB (RFC 2674).
 Ether-Like MIB (RFC 2358) – dot3StatsTable.

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
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• Supports Web-based management.
• CLI management support.
• TFTP support.
• BOOTP support.
• DHCP Client support.
• Password enabled.
Fast Ethernet Technology
100Mbps Fast Ethernet (or 100BASE-T) is a standard specified
by the IEEE 802.3 LAN committee. It is an extension of the
10Mbps Ethernet standard with the ability to transmit and
receive data at 100Mbps, while maintaining the Carrier Sense
Multiple Access with Collision Detection (CSMA/CD) Ethernet
protocol.
Gigabit Ethernet Technology
Gigabit Ethernet is an extension of IEEE 802.3 Ethernet
utilizing the same packet structure, format, and support for
full duplex and management objects, but with a tenfold
increase in theoretical throughput over 100Mbps Fast Ethernet
and a one hundred-fold increase over 10Mbps Ethernet. Since
it is compatible with all 10Mbps and 100Mbps Ethernet
environments, Gigabit Ethernet provides a straightforward
upgrade without wasting a company’s existing investment in
hardware, software, and trained personnel.

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
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2
UNPACKING AND SETUP
This chapter provides unpacking and setup information for the
Switch.
Unpacking
Open the shipping carton of the Switch and carefully unpack
its contents. The carton should contain the following items:
• One DES-3250TG Standalone Layer 2 Switch
• Mounting kit: 2 mounting brackets and screws
• Four rubber feet with adhesive backing
• One AC power cord
• This User’s Guide with Registration Card
If any item is found missing or damaged, please contact your
local D-Link reseller for replacement.

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
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Installation
Use the following guidelines when choosing a place to install
the Switch:
• The surface must support at least 3 kg
• The power outlet should be within 1.82 meters (6
feet) of the device
• Visually inspect the power cord and see that it is
secured to the AC power connector
• Make sure that there is proper heat dissipation from
and adequate ventilation around the switch. Do not
place heavy objects on the switch
Desktop or Shelf Installation
When installing the Switch on a desktop or shelf, the rubber
feet included with the device should first be attached. Attach
these cushioning feet on the bottom at each corner of the
device. Allow adequate space for ventilation between the device
and the objects around it.

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
Figure 2-1. Installing rubber feet for desktop installation
Rack Installation
The DES-3250TG can be mounted in an EIA standard-sized,
19-inch rack, which can be placed in a wiring closet with other
equipment. To install, attach the mounting brackets on the
switch’s side panels (one on each side) and secure them with
the screws provided.
Figure 2- 2. Attaching the mounting brackets to the switch
Then, use the screws provided with the equipment rack to
mount the switch on the rack.
8

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
Figure 2-3. Installing the switch on an equipment rack
Power on
The DES-3250TG switch can be used with AC power supply
100 - 240 VAC, 50 - 60 Hz. The power switch is located at the
rear of the unit adjacent to the AC power connector and the
system fan. The switch’s power supply will adjust to the local
power source automatically and may be turned on without
having any or all LAN segment cables connected.
After the power switch is turned on, the LED indicators should
respond as follows:
9

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
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• All LED indicators will momentarily blink. This
blinking of the LED indicators represents a reset of
the system
• The power LED indicator is always on after the power
is turned ON
• The console LED indicator will blink while the Switch
loads onboard software and performs a self-test. It
will remain ON if there is a connection at the RS-232
port, otherwise this LED indicator is OFF
Power Failure
As a precaution in the event of a power failure, unplug the
switch. When the power supply is restored, plug the switch
back in.

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
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3
IDENTIFYING EXTERNAL
COMPONENTS
This chapter describes the front panel, rear panel, side panels,
and optional plug-in module, and LED indicators of the
DES-3250TG.
Front Panel
The front panel of the Switch consists of LED indicators, an
RS-232 communication port, 48 (10/100 Mbps) Ethernet/Fast
Ethernet ports, and a pair of Gigabit Ethernet Combo ports for
1000BASE-T (plug-in module provided) and Mini GBIC
connections (optional plug-in module).
Figure 3-1. Front panel view of the Switch
●Comprehensive LED indicators display the status of
the switch and the network (see the LED Indicators
section below).

DES-3250TG Layer 2 Fast Ethernet Switch User’s Guide
●An RS-232 DCE console port for setting up and
managing the switch via a connection to a console
terminal or PC using a terminal emulation program.
●Forty-eight high-performance NWay Ethernet ports,
all of which operate at 10/100 Mbps for connections
to end stations, servers and hubs. All ports can auto-
negotiate between 10Mbps or 100Mbps and full or
half duplex.
●Two Gigabit Ethernet Combo ports for making
1000BASE-T and Mini GBIC connections.
Rear Panel
The rear panel of the switch consists of two fans and an AC
power connector.
Figure 3-2. Rear panel view of the Switch
The system fans are used to dissipate heat. The sides of the
system also provide heat vents to serve the same purpose. Do
not block these openings, and leave at least 6 inches of space
at the rear and sides of the switch for proper ventilation. Be
reminded that without proper heat dissipation and air
circulation, system components might overheat, which could
lead to system failure. The AC power connector is a standard
three-pronged connector that supports the power cord. Plug-in
the female connector of the provided power cord into this
socket, and the male side of the cord into a power outlet.
Supported input voltages range from 100 ~ 240 VAC at 50 ~ 60
Hz.
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