Smc 8028L2 Management Guide
MANAGEMENT GUIDE
SMC8028L2
TigerSwitchTM 10/100/1000
28-Port Gigabit Ethernet Switch
TigerSwitch 10/100/1000
Management Guide
From SMC's Tiger line of feature-rich workgroup LAN solutions
20 Mason
Irvine, CA 92618
Phone: (949) 679-8000
Janurary 2010
Pub. # 149100000079A
E012010-MW-R01
Information furnished by SMC Networks, Inc. (SMC) is believed to be accurate and reliable.
However, no responsibility is assumed by SMC for its use, nor for any infringements of patents or
other rights of third parties which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of SMC. SMC reserves the right to change specifications
at any time without notice.
Copyright © 2010 by
SMC Networks, Inc.
20 Mason
Irvine, CA 92618
All rights reserved
Trademarks:
SMC is a registered trademark; and EZ Switch, TigerStack, TigerSwitch, and TigerAccess are
trademarks of SMC Networks, Inc. Other product and company names are trademarks or registered
trademarks of their respective holders.
WARRANTY AND PRODUCT REGISTRATION
To register SMC products and to review the detailed warranty statement,
please refer to the Support Section of the SMC Website at
http://www.smc.com.
– 4 –
ABOUT THIS GUIDE
PURPOSE This guide gives specific information on how to operate and use the
management functions of the switch.
AUDIENCE The guide is intended for use by network administrators who are
responsible for operating and maintaining network equipment;
consequently, it assumes a basic working knowledge of general switch
functions, the Internet Protocol (IP), and Simple Network Management
Protocol (SNMP).
CONVENTIONS The following conventions are used throughout this guide to show
information:
N
OTE
:
Emphasizes important information or calls your attention to related
features or instructions.
C
AUTION
damage the system or equipment.
W
ARNING
:
Alerts you to a potential hazard that could cause loss of data, or
:
Alerts you to a potential hazard that could cause personal injury.
RELATED PUBLICATIONS The following publication details the hardware features of the switch,
including the physical and performance-related characteristics, and how to
install the switch:
The Installation Guide
Also, as part of the switch’s software, there is an online web-based help
that describes all management related features.
REVISION HISTORY This section summarizes the changes in each revision of this guide.
JANURARY 2010 REVISION
This is the first version of this guide. This guide is valid for software release
v1.12.
– 5 –
A
BOUT THIS GUIDE
– 6 –
CONTENTS
WARRANTY AND PRODUCT REGISTRATION 4
BOUT THIS GUIDE 5
A
ONTENTS 7
C
IGURES 19
F
ABLES 23
T
SECTION I GETTING STARTED 25
1INTRODUCTION 27
Key Features 27
Description of Software Features 28
Configuration Backup and Restore 28
Authentication 28
Access Control Lists 29
Port Configuration 29
Rate Limiting 29
Port Mirroring 29
Port Trunking 29
Storm Control 29
Static Addresses 29
IEEE 802.1D Bridge 30
Store-and-Forward Switching 30
Spanning Tree Algorithm 30
Virtual LANs 31
Traffic Prioritization 31
Quality of Service 32
Multicast Filtering 32
System Defaults 33
2INITIAL SWITCH CONFIGURATION 35
Connecting to the Switch 35
– 7 –
C
ONTENTS
Configuration Options 35
Required Connections 36
Remote Connections 37
Basic Configuration 38
Setting Passwords 38
Setting an IP Address 38
Enabling SNMP Management Access 41
Managing System Files 45
Saving or Restoring Configuration Settings 45
SECTION II WEB CONFIGURATION 47
3USING THE WEB INTERFACE 49
Connecting to the Web Interface 49
Navigating the Web Browser Interface 50
Home Page 50
Configuration Options 50
Panel Display 51
Main Menu 51
4CONFIGURING THE SWITCH 55
Configuring System Information 55
Setting an IP Address 56
Setting an IPv4 Address 56
Setting an IPv6 Address 58
Setting the System Password 61
Filtering IP Addresses for Management Access 61
Configuring Port Connections 63
Configuring Authentication for Management Access and 802.1X 65
Creating Trunk Groups 69
Configuring Static Trunks 70
Configuring LACP 73
Configuring the Spanning Tree Algorithm 75
Configuring Global Settings for STA 76
Configuring Interface Settings for STA 78
Configuring 802.1X Port Authentication 81
Configuring HTTPS 87
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C
ONTENTS
Configuring SSH 88
IGMP Snooping 89
Configuring IGMP Snooping and Query 90
Configuring IGMP Filtering 94
Configuring Link Layer Discovery Protocol 95
Configuring the MAC Address Table 98
IEEE 802.1Q VLANs 100
Assigning Ports to VLANs 101
Configuring VLAN Attributes for Port Members 102
Configuring Private VLANs 104
Using Port Isolation 105
Quality of Service 106
Configuring Port-Level Queue Settings 107
Configuring DSCP Remarking 108
Configuring QoS Control Lists 110
Configuring Rate Limiting 113
Configuring Storm Control 115
Access Control Lists 117
Assigning ACL Policies and Responses 117
Configuring Rate Limiters 118
Configuring Access Control Lists 119
Configuring Port Mirroring 127
Simple Network Management Protocol 128
Configuring SNMP System and Trap Settings 129
Setting SNMPv3 Community Access Strings 134
Configuring SNMPv3 Users 135
Configuring SNMPv3 Groups 136
Configuring SNMPv3 Views 138
Configuring SNMPv3 Group Access Rights 139
Configuring UPnP 140
Configuring DHCP Relay and Option 82 Information 142
5MONITORING THE SWITCH 145
Displaying Basic Information About the System 145
Displaying System Information 145
Displaying Log Messages 146
Displaying Log Details 148
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C
ONTENTS
Displaying Access Management Statistics 148
Displaying Information About Ports 149
Displaying Port Status On the Front Panel 149
Displaying an Overview of Port Statistics 150
Displaying QoS Statistics 151
Displaying Detailed Port Statistics 152
Displaying Information on Authentication Servers 155
Displaying a List of Authentication Servers 155
Displaying Statistics for Configured Authentication Servers 156
Displaying Information on LACP 161
Displaying an Overview of LACP Groups 161
Displaying LACP Port Status 161
Displaying LACP Port Statistics 163
Displaying Information on the Spanning Tree 164
Displaying Bridge Status for STA 164
Displaying Port Status for STA 166
Displaying Port Statistics for STA 167
Displaying Port Security Information 168
Displaying Port Security Status 168
Displaying Port Security Statistics 169
Showing IGMP Snooping Information 173
Displaying LLDP Information 174
Displaying LLDP Neighbor Information 174
Displaying LLDP Port Statistics 176
Displaying DHCP Relay Statistics 177
Displaying the MAC Address Table 179
6PERFORMING BASIC DIAGNOSTICS 181
Pinging an IPv4 or IPv6 Address 181
Running Cable Diagnostics 182
7PERFORMING SYSTEM MAINTENANCE 185
Resetting the Switch 185
Restoring Factory Defaults 186
Upgrading Firmware 186
Managing Configuration Files 187
Saving Configuration Settings 187
Restoring Configuration Settings 188
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C
ONTENTS
SECTION III COMMAND LINE INTERFACE 189
8USING THE COMMAND LINE INTERFACE 191
Accessing the CLI 191
Console Connection 191
Telnet Connection 192
Entering Commands 193
Keywords and Arguments 193
Minimum Abbreviation 194
Getting Help on Commands 194
Partial Keyword Lookup 195
Using Command History 196
Command Line Processing 196
CLI Command Groups 197
9SYSTEM COMMANDS 199
system configuration 200
system reboot 200
system restore default 201
system contact 201
system name 201
system location 202
system password 202
system timezone 203
system log 203
system access configuration 204
system access mode 204
system access add 205
system access ipv6 add 206
system access delete 207
system access lookup 207
system access clear 207
system access statistics 207
10 IP COMMANDS 209
ip configuration 209
ip dhcp 210
ip setup 211
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C
ONTENTS
ip ping 212
ip dns 213
ip dns_proxy 213
ip sntp 214
ip ipv6 autoconfig 214
ip ipv6 setup 215
ip ipv6 ping6 216
ip ipv6 sntp 217
11 AUTHENTICATION COMMANDS 219
auth configuration 219
auth timeout 220
auth deadtime 221
auth radius 221
auth acct_radius 222
auth tacacs+ 224
auth client 225
auth statistics 226
12 PORT COMMANDS 229
port configuration 229
port state 231
port mode 231
port flow control 232
port maxframe 233
port power 233
port excessive 234
port statistics 235
port veriphy 236
port numbers 237
13 LINK AGGREGATION COMMANDS 239
aggr configuration 240
aggr add 241
aggr delete 241
aggr lookup 242
aggr mode 242
14 LACP COMMANDS 245
lacp configuration 247
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C
ONTENTS
lacp mode 247
lacp key 248
lacp role 248
lacp status 249
lacp statistics 249
15 RSTP COMMANDS 251
rstp configuration 252
rstp sysprio 252
rstp age 253
rstp delay 253
rstp txhold 254
rstp version 254
rstp mode 255
rstp cost 255
rstp priority 257
rstp edge 257
rstp autoedge 258
rstp p2p 259
rstp status 259
rstp statistics 260
rstp mcheck 260
16 IEEE 802.1X COMMANDS 263
dot1x configuration 263
dot1x mode 265
dot1x state 265
dot1x authenticate 266
dot1x reauthentication 267
dot1x period 268
dot1x timeout 268
dot1x clients 268
dot1x agetime 269
dot1x holdtime 270
dot1x statistics 270
17 IGMP COMMANDS 273
igmp configuration 273
igmp mode 275
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C
ONTENTS
igmp state 275
igmp querier 276
igmp fastleave 277
igmp leave proxy 278
igmp throttling 278
igmp filtering 279
igmp router 280
igmp flooding 280
igmp groups 281
igmp status 281
18 LLDP COMMANDS 283
lldp configuration 283
lldp mode 284
lldp optional_tlv 284
lldp interval 285
lldp hold 286
lldp delay 286
lldp reinit 287
lldp info 287
lldp statistics 288
lldp cdp_aware 289
19 MAC COMMANDS 291
mac configuration 291
mac add 292
mac delete 292
mac lookup 293
mac agetime 293
mac learning 293
mac dump 294
mac statistics 295
mac flush 295
20 VLAN COMMANDS 297
vlan configuration 297
vlan aware 298
vlan pvid 299
vlan frametype 299
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C
ONTENTS
vlan ingressfilter 300
vlan qinq 300
vlan add 301
vlan delete 301
vlan lookup 302
21 PVLAN COMMANDS 303
pvlan configuration 303
pvlan add 304
pvlan delete 304
pvlan lookup 305
pvlan isolate 305
22 QOS COMMANDS 307
qos configuration 308
qos default 308
qos tagprio 309
qos qcl port 309
qos qcl add 310
qos qcl delete 311
qos qcl lookup 312
qos mode 312
qos weight 313
qos rate limiter 313
qos shaper 314
qos storm unicast 315
qos storm multicast 315
qos storm broadcast 316
qos dscp remarking 316
qos dscp queue mapping 317
23 ACL COMMANDS 319
acl configuration 319
acl action 320
acl policy 321
acl rate 321
acl add 322
acl delete 325
acl lookup 325
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C
ONTENTS
acl clear 326
24 MIRROR COMMANDS 327
mirror configuration 327
mirror port 327
mirror mode 328
25 CONFIG COMMANDS 329
config save 329
config load 330
26 SNMP COMMANDS 331
snmp configuration 332
snmp mode 333
snmp version 334
snmp read community 334
snmp write community 335
snmp trap mode 335
snmp trap version 336
snmp trap community 336
snmp trap destination 337
snmp trap ipv6 destination 337
snmp trap authentication failure 337
snmp trap link-up 338
snmp trap inform mode 338
snmp trap inform timeout 339
snmp trap inform retry times 339
snmp trap probe security engine id 340
snmp trap security engine id 340
snmp trap security name 341
snmp engine id 341
snmp community add 342
snmp community delete 342
snmp community lookup 343
snmp user add 343
snmp user delete 344
snmp user changekey 345
snmp user lookup 345
snmp group add 346
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C
ONTENTS
snmp group delete 347
snmp group lookup 347
snmp view add 348
snmp view delete 348
snmp view lookup 349
snmp access add 349
snmp access delete 350
snmp access lookup 350
27 HTTPS COMMANDS 353
https configuration 353
https mode 353
https redirect 354
28 SSH COMMANDS 357
ssh configuration 357
ssh mode 357
29 UPNP COMMANDS 359
upnp configuration 359
upnp mode 359
upnp ttl 360
upnp advertising duration 361
30 DHCP COMMANDS 363
dhcp relay configuration 363
dhcp relay mode 363
dhcp relay server 364
dhcp relay information mode 364
dhcp relay information policy 365
dhcp relay statistics 365
31 FIRMWARE COMMANDS 367
firmware load 367
firmware ipv6 load 368
SECTION IV APPENDICES 371
ASOFTWARE SPECIFICATIONS 373
Software Features 373
Management Features 374
– 17 –
C
ONTENTS
Standards 375
Management Information Bases 375
BTROUBLESHOOTING 377
Problems Accessing the Management Interface 377
Using System Logs 378
GLOSSARY 379
NDEX 387
I
– 18 –
FIGURES
Figure 1: Home Page 50
Figure 2: Front Panel Indicators 51
Figure 3: System Information Configuration 56
Figure 4: IP & Time Configuration 58
Figure 5: IPv6 & Time Configuration 60
Figure 6: System Password 61
Figure 7: Access Management Configuration 62
Figure 8: Port Configuration 64
Figure 9: Authentication Configuration 68
Figure 10: Static Trunk Configuration 72
Figure 11: LACP Port Configuration 75
Figure 12: RSTP System Configuration 78
Figure 13: RSTP Port Configuration 80
Figure 14: Port Security Configuration 86
Figure 15: HTTPS Configuration 88
Figure 16: SSH Configuration 89
Figure 17: IGMP Snooping Configuration 93
Figure 18: IGMP Snooping Port Group Filtering Configuration 94
Figure 19: LLDP Configuration 98
Figure 20: MAC Address Table Configuration 100
Figure 21: VLAN Membership Configuration 102
Figure 22: VLAN Port Configuration 104
Figure 23: Private VLAN Membership Configuration 105
Figure 24: Port Isolation Configuration 106
Figure 25: Port QoS Configuration 108
Figure 26: DSCP Remarking Configuration 110
Figure 27: QoS Control List Configuration 113
Figure 28: Rate Limit Configuration 114
Figure 29: Storm Control Configuration 116
Figure 30: ACL Port Configuration 118
Figure 31: ACL Rate Limiter Configuration 119
– 19 –
F
IGURES
Figure 32: Access Control List Configuration 126
Figure 33: Mirror Configuration 127
Figure 34: SNMP System Configuration 133
Figure 35: SNMPv3 Communities Configuration 134
Figure 36: SNMPv3 Users Configuration 136
Figure 37: SNMPv3 Group Configuration 137
Figure 38: SNMPv3 View Configuration 138
Figure 39: SNMPv3 Access Configuration 140
Figure 40: UPnP Configuration 141
Figure 41: DHCP Relay Configuration 143
Figure 42: System Information 146
Figure 43: System Log Information 147
Figure 44: Detailed System Log Information 148
Figure 45: Access Management Statistics 149
Figure 46: Port State Overview 149
Figure 47: Port Statistics Overview 150
Figure 48: Queuing Counters 151
Figure 49: Detailed Port Statistics 154
Figure 50: RADIUS Overview 156
Figure 51: RADIUS Details 160
Figure 52: LACP System Status 161
Figure 53: LACP Port Status 162
Figure 54: LACP Port Statistics 163
Figure 55: Spanning Tree Bridge Status 166
Figure 56: Spanning Tree Port Status 167
Figure 57: Spanning Tree Port Statistics 168
Figure 58: Port Security Status 169
Figure 59: Port Security Statistics 172
Figure 60: IGMP Snooping Status 174
Figure 61: LLDP Neighbor Information 175
Figure 62: LLDP Port Statistics 177
Figure 63: DHCP Relay Statistics 179
Figure 64: MAC Address Table 180
Figure 65: ICMP Ping 182
Figure 66: VeriPHY Cable Diagnostics 183
Figure 67: Reset Device 185
– 20 –
F
IGURES
Figure 68: Factory Defaults 186
Figure 69: Software Upload 187
Figure 70: Configuration Save 187
Figure 71: Configuration Upload 188
– 21 –
F
IGURES
– 22 –
TABLES
Table 1: Key Features 27
Table 2: System Defaults 33
Table 3: Web Page Configuration Buttons 50
Table 4: Main Menu 51
Table 5: Recommended STA Path Cost Range 79
Table 6: Recommended STA Path Costs 79
Table 7: Default STA Path Costs 79
Table 8: HTTPS System Support 87
Table 9: QCE Modification Buttons 111
Table 10: Mapping CoS Values to Egress Queues 112
Table 11: QCE Modification Buttons 121
Table 12: SNMP Security Models and Levels 129
Table 13: System Capabilities 175
Table 14: Keystroke Commands 196
Table 15: Command Group Index 197
Table 16: System Commands 199
Table 17: IP Commands 209
Table 18: Authentication Commands 219
Table 19: Port Commands 229
Table 20: Port Configuration 229
Table 21: Link Aggregation Commands 239
Table 22: LACP Commands 245
Table 23: RSTP Commands 251
Table 24: Recommended STA Path Cost Range 256
Table 25: Recommended STA Path Costs 256
Table 26: Default STA Path Costs 256
Table 27: IEEE 802.1X Commands 263
Table 28: 802.1X Configuration 264
Table 29: IGMP Commands 273
Table 30: IGMP Configuration 274
Table 31: LLDP Commands 283
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T
ABLES
Table 32: MAC Commands 291
Table 33: VLAN Commands 297
Table 34: PVLAN Commands 303
Table 35: QoS Commands 307
Table 36: Mapping CoS Values to Egress Queues 310
Table 37: ACL Commands 319
Table 38: Mirror Commands 327
Table 39: Configuration Commands 329
Table 40: SNMP Commands 331
Table 41: HTTPS Commands 353
Table 42: HTTPS System Support 354
Table 43: SSH Commands 357
Table 44: UPnP Commands 359
Table 45: DHCP Commands 363
Table 46: Firmware Commands 367
Table 47: Troubleshooting Chart 377
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S
ECTION
GETTING STARTED
This section provides an overview of the switch, and introduces some basic
concepts about network switches. It also describes the basic settings
required to access the management interface.
This section includes these chapters:
◆ "Introduction" on page 27
◆ "Initial Switch Configuration" on page 35
I
– 25 –
S
ECTION
| Getting Started
– 26 –
1 INTRODUCTION
This switch provides a broad range of features for Layer 2 switching. It
includes a management agent that allows you to configure the features
listed in this manual. The default configuration can be used for most of the
features provided by this switch. However, there are many options that you
should configure to maximize the switch’s performance for your particular
network environment.
KEY FEATURES
Table 1: Key Features
Feature Description
Configuration Backup
and Restore
Backup to management station or TFTP server
Authentication Console, Telnet, web – user name/password, RADIUS, TACACS+
Access Control Lists Supports up to 128 rules
DHCP Client Supported
DNS Proxy service
Port Configuration Speed, duplex mode, flow control, MTU, response to excessive
Rate Limiting Input rate limiting per port (using ACL)
Port Mirroring One or more ports mirrored to single analysis port
Port Trunking Supports up to 14 trunks using either static or dynamic trunking
Storm Control Throttling for broadcast, multicast, and unknown unicast storms
Address Table Up to 8K MAC addresses in the forwarding table, 1024 static MAC
IP Version 4 and 6 Supports IPv4 and IPv6 addressing, management, and QoS
IEEE 802.1D Bridge Supports dynamic data switching and addresses learning
Store-and-Forward
Switching
Web – HTTPS
Teln e t – SS H
SNMP v1/2c - Community strings
SNMP version 3 – MD5 or SHA password
Port – IEEE 802.1X, MAC address filtering
DHCP Snooping (with Option 82 relay information)
IP Source Guard
collisions, power saving mode
(LACP)
addresses
Supported to ensure wire-speed switching while eliminating bad
frames
Spanning Tree Algorithm Supports Rapid Spanning Tree Protocol (RSTP), which includes
STP backward compatible mode
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C
HAPTER
Description of Software Features
1
| Introduction
Table 1: Key Features (Continued)
Feature Description
Virtual LANs Up to 256 using IEEE 802.1Q, port-based, and private VLANs
Traffic Prioritization Queue mode and CoS configured by Ethernet type, VLAN ID, TCP/
Qualify of Service Supports Differentiated Services (DiffServ), and DSCP remarking
Multicast Filtering Supports IGMP snooping and query
DESCRIPTION OF SOFTWARE FEATURES
The switch provides a wide range of advanced performance enhancing
features. Flow control eliminates the loss of packets due to bottlenecks
caused by port saturation. Storm suppression prevents broadcast,
multicast, and unknown unicast traffic storms from engulfing the network.
Untagged (port-based) and tagged VLANs, plus support for automatic
GVRP VLAN registration provide traffic security and efficient use of network
bandwidth. CoS priority queueing ensures the minimum delay for moving
real-time multimedia data across the network. While multicast filtering
provides support for real-time network applications.
UDP port, DSCP, ToS bit, VLAN tag priority, or port
Some of the management features are briefly described below.
CONFIGURATION
BACKUP AND
RESTORE
You can save the current configuration settings to a file on the
management station (using the web interface) or a TFTP server (using the
console interface), and later download this file to restore the switch
configuration settings.
AUTHENTICATION This switch authenticates management access via the console port, Telnet,
or a web browser. User names and passwords can be configured locally or
can be verified via a remote authentication server (i.e., RADIUS or
TACACS+). Port-based authentication is also supported via the IEEE
802.1X protocol. This protocol uses Extensible Authentication Protocol over
LANs (EAPOL) to request user credentials from the 802.1X client, and then
uses the EAP between the switch and the authentication server to verify
the client’s right to access the network via an authentication server (i.e.,
RADIUS server).
Other authentication options include HTTPS for secure management access
via the web, SSH for secure management access over a Telnet-equivalent
connection, SNMP Version 3, IP address filtering for web/SNMP/Telnet/SSH
management access, and MAC address filtering for port access.
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C
HAPTER
Description of Software Features
1
| Introduction
ACCESS CONTROL
LISTS
ACLs provide packet filtering for IP frames (based on protocol, TCP/UDP
port number or frame type) or layer 2 frames (based on any destination
MAC address for unicast, broadcast or multicast, or based on VLAN ID or
VLAN tag priority). ACLs can by used to improve performance by blocking
unnecessary network traffic or to implement security controls by restricting
access to specific network resources or protocols. Policies can be used to
differentiate service for client ports, server ports, network ports or guest
ports. They can also be used to strictly control network traffic by only
allowing incoming frames that match the source MAC and source IP on
specific port.
PORT CONFIGURATION You can manually configure the speed and duplex mode, and flow control
used on specific ports, or use auto-negotiation to detect the connection
settings used by the attached device. Use the full-duplex mode on ports
whenever possible to double the throughput of switch connections. Flow
control should also be enabled to control network traffic during periods of
congestion and prevent the loss of packets when port buffer thresholds are
exceeded. The switch supports flow control based on the IEEE 802.3x
standard (now incorporated in IEEE 802.3-2002).
RATE LIMITING This feature controls the maximum rate for traffic transmitted or received
on an interface. Rate limiting is configured on interfaces at the edge of a
network to limit traffic into or out of the network. Traffic that falls within
the rate limit is transmitted, while packets that exceed the acceptable
amount of traffic are dropped.
PORT MIRRORING The switch can unobtrusively mirror traffic from any port to a monitor port.
You can then attach a protocol analyzer or RMON probe to this port to
perform traffic analysis and verify connection integrity.
PORT TRUNKING Ports can be combined into an aggregate connection. Trunks can be
manually set up or dynamically configured using Link Aggregation Control
Protocol (LACP – IEEE 802.3-2005). The additional ports dramatically
increase the throughput across any connection, and provide redundancy by
taking over the load if a port in the trunk should fail. The switch supports
up to 14 trunks.
STORM CONTROL Broadcast, multicast and unknown unicast storm suppression prevents
traffic from overwhelming the network.When enabled on a port, the level of
broadcast traffic passing through the port is restricted. If broadcast traffic
rises above a pre-defined threshold, it will be throttled until the level falls
back beneath the threshold.
STATIC ADDRESSES A static address can be assigned to a specific interface on this switch.
Static addresses are bound to the assigned interface and will not be
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C
HAPTER
Description of Software Features
1
| Introduction
moved. When a static address is seen on another interface, the address will
be ignored and will not be written to the address table. Static addresses
can be used to provide network security by restricting access for a known
host to a specific port.
IEEE 802.1D BRIDGE The switch supports IEEE 802.1D transparent bridging. The address table
facilitates data switching by learning addresses, and then filtering or
forwarding traffic based on this information. The address table supports up
to 8K addresses.
STORE-AND-FORWARD
SWITCHING
SPANNING TREE
ALGORITHM
The switch copies each frame into its memory before forwarding them to
another port. This ensures that all frames are a standard Ethernet size and
have been verified for accuracy with the cyclic redundancy check (CRC).
This prevents bad frames from entering the network and wasting
bandwidth.
To avoid dropping frames on congested ports, the switch provides 0.75 MB
for frame buffering. This buffer can queue packets awaiting transmission
on congested networks.
The switch supports these spanning tree protocols:
◆ Spanning Tree Protocol (STP, IEEE 802.1D) – Supported by using the
STP backward compatible mode provided by RSTP. STP provides loop
detection. When there are multiple physical paths between segments,
this protocol will choose a single path and disable all others to ensure
that only one route exists between any two stations on the network.
This prevents the creation of network loops. However, if the chosen
path should fail for any reason, an alternate path will be activated to
maintain the connection.
◆ Rapid Spanning Tree Protocol (RSTP, IEEE 802.1w) – This protocol
reduces the convergence time for network topology changes to about 3
to 5 seconds, compared to 30 seconds or more for the older IEEE
802.1D STP standard. It is intended as a complete replacement for STP,
but can still interoperate with switches running the older standard by
automatically reconfiguring ports to STP-compliant mode if they detect
STP protocol messages from attached devices.
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