Cisco Systems BC-23 - page 58

Configuring Transparent Bridging

Transparent and SRT Bridging Configuration Examples

BC-80

Cisco IOS Bridging and IBM Networking Configuration Guide

Note To get spanning-tree information by bridge group, use the show span command. Included

in this information is the root bridge of the spanning tree. The root bridge for each spanning

tree can be any router in the spanning tree.

The routers in this network are configured for bridging and demonstrate some of the bridging features

available.

Configuration for Router A

Router A demonstrates multiple bridge groups in one router for bridged traffic separation.

In Router A, the Token Ring interfaces are bridged together entirely independently of the other bridged

interfaces in the router and belong to bridge group 1. Bridge group 1 does not use a bridge domain

because the interfaces are bridged independently of other bridged subnetworks in the network topology

and it has no connection to the FDDI backbone.

Also in Router A, the Ethernet interfaces belong to bridge group 3. Bridge group 3 has a connection to

the FDDI backbone and has a domain defined for it so that it can ignore BPDUs for other bridged

subnetworks.

interface ethernet 0

bridge-group 3

!

interface ethernet 1

bridge-group 3

!

interface ethernet 2

bridge-group 3

!

interface ethernet 3

bridge-group 3

!

interface fddi 0

bridge-group 3

!

interface tokenring 1

bridge-group 1

!

interface tokenring 2

bridge-group 1

!

bridge 1 protocol ieee

bridge 3 domain 1

bridge 3 protocol ieee

Contents

Main Configuring Transparent Bridging Technology Overview Transparent and SRT Bridging Transparent Bridging Features Integrated Routing and Bridging Bridge-Group Virtual Interface Page Other Considerations SRT Bridging Features Transparent and SRT Bridging Configuration Task List Configuring Transparent Bridging and SRT Bridging Assigning a Bridge Group Number and Defining the Spanning-Tree Protocol Assigning Each Network Interface to a Bridge Group Choosing the OUI for Ethernet Type II Frames Transparently Bridged VLANs for ISL Page Routing between ISL VLANs Page Configuring a Subscriber Bridge Group Configuring Transparent Bridging over WANs Configuring Fast-Switched Transparent Bridging over ATM Configuring Transparent Bridging over DDR Configuring Transparent Bridging over Frame Relay Configuring Transparent Bridging over Multiprotocol LAPB Configuring Transparent Bridging over SMDS Configuring Transparent Bridging over X.25 Configuring Concurrent Routing and Bridging Configuring Integrated Routing and Bridging Assigning a Bridge Group Number and Defining the Spanning-Tree Protocol Configuring Interfaces Enabling Integrated Routing and Bridging Configuring the Bridge-Group Virtual Interface Configuring Protocols for Routing or Bridging Configuring Transparent Bridging Options Disabling IP Routing Enabling Autonomous Bridging Configuring LAT Compression Establishing Multiple Spanning-Tree Domains Preventing the Forwarding of Dynamically Determined Stations Forwarding Multicast Addresses Configuring Bridge Table Aging Time Filtering Transparently Bridged Packets Setting Filters at the MAC Layer Filtering by Specific MAC Address Page Page Page Filtering LAT Service Announcements Specifying Deny or Permit Conditions for LAT Group Codes on Output Adjusting Spanning-Tree Parameters Setting the Bridge Priority Setting an Interface Priority Assigning Path Costs Adjusting BPDU Intervals Disabling the Spanning Tree on an Interface Configuring Transparent and IRB Bridging on a PA-12E/2FE Ethernet Switch Configuring the PA-12E/2FE Port Adapter Monitoring and Maintaining the PA-12E/2FE Port Adapter Configuring Bridge Groups Using the 12E/2FE VLAN Configuration WebTool Page Tuning the Transparently Bridged Network Configuring Circuit Groups Configuring Constrained Multicast Flooding Monitoring and Maintaining the Transparent Bridge Network Transparent and SRT Bridging Configuration Examples Basic Bridging Example BC-64 The configuration file for the router in Figure 12 is as follows: Concurrent Routing and Bridging Example BC-65 Basic Integrated Routing and Bridging Example Figure 13 Basic IP Routing using Integrated Routing and Bridging The following example shows the relevant portions of the configuration for the router in Figure 13: BC-66 Complex Integrated Routing and Bridging Example Figure 14 Complex Integrated Routing and Bridging Example The following example shows the relevant portions of the configuration for the router: BC-67 Integrated Routing and Bridging with Multiple Bridge Groups Example Figure 15 Integrated Routing and Bridging with Multiple Bridge Groups The following example shows the relevant portions of the configuration for the router in Figure 15: Transparently Bridged VLANs Configuration Example BC-68 Router One Router Two BC-69 Router Three BC-70 Routing between VLANs Configuration Example Ethernet-to-FDDI Transparent Bridging Example Ethernet Bridging Example SRT Bridging Example BC-73 Configuration for the New York City Router Configuration for the Thule, Greenland Router Multicast or Broadcast Packets Bridging Example Figure 18 Network Demonstrating Output Address List Filtering BC-74 The correct access list would be as follows: X.25 Transparent Bridging Example Figure 19 X.25 Bridging Examples Following are the configuration commands for each of the bridges depicted in Figure19: X.25 Bridge 2 Bridge 1 Bridge 3 BC-75 Frame Relay Transparent Bridging Examples Figure 20 illustrates three bridges connected to each other through a Frame Relay network. Figure 20 Frame Relay Bridging Example Bridging in a Frame Relay Network with No Multicasts Bridge 2 Bridge 1 Bridge 3 Transparent Bridging over Multiprotocol LAPB Example BC-77 Fast-Switched Transparent Bridging over ATM Example (Cisco 7000) The following configuration example enables fast-switched transparent bridging over ATM: Transparent Bridging over DDR Examples Fast-Switched Transparent Bridging over SMDS Example Complex Transparent Bridging Network Topology Example Page Page Page BC-82 Fast Ethernet Subscriber Port, Frame Relay Trunk Example ATM Subscriber Ports, ATM Trunk Example The following example uses ATM subinterfaces as the subscriber ports and the ATM as the trunk: BC-83 Configuration of Transparent Bridging for PA-12E/2FE Port Adapter Example BC-84 Configuration of IRB for PA-12E/2FE Port Adapter Example