Configuration Examples

This section provides examples that show how to configure transparent bridging on the router. With each step, an illustration shows how the router is building the interface column.

Example 1: Bridging with Bridged Ethernet

The following example illustrates how to configure transparent bridging with bridged Ethernet.

1. Create the bridge group.
   host1(config)#bridge westford01
2. Create an ATM major interface.
   host1(config)#interface atm 3/3
   
3. Create an ATM 1483 subinterface and associated PVC.
   host1(config-if)#interface atm 3/3.1 host1(config-subif)#atm pvc 1 0 10 aal5snap
   
4. Specify bridged Ethernet as the encapsulation method on the subinterface. The encapsulation keyword implies that the bridged Ethernet interface is the only interface stacked directly above the ATM 1483 subinterface. As a result, the bridged Ethernet interface cannot have a peer interface stacked above the same lower-layer interface.
   host1(config-subif)#encapsulation bridge1483
   
5. Create a PPPoE major interface over the bridged Ethernet interface. Because this command does not use the encapsulation keyword, the PPPoE interface can have one or more peer interfaces stacked above the same bridged Ethernet interface.
   host1(config-subif)#pppoe
   
6. Configure a subscriber (client) bridge group interface over the bridged Ethernet interface as a peer to the PPPoE interface. Assign the interface to the bridge group you created in Step 1.
   host1(config-subif)#bridge-group westford01
   

Example 2: Bridging with VLANs

The following example illustrates how to configure transparent bridging with VLANs over a Fast Ethernet interface.

Note: You can also configure transparent bridging with VLANs over a bridged Ethernet interface. For information, see Configuring VLANs over Bridged Ethernet in Configuring Bridged Ethernet.

1. Create the bridge group.
   host1(config)#bridge westford02
2. Create a Fast Ethernet interface.
   host1(config)#interface fastEthernet 2/0
   
3. Create a VLAN major interface by specifying VLAN as the encapsulation method for the interface.
   host1(config-if)#encapsulation vlan
   
4. Create a VLAN subinterface by adding a subinterface number to the interface fastEthernet command.
   host1(config-if)#interface fastEthernet 2/0.1
   
5. Assign a unique VLAN ID to the VLAN subinterface.
   host1(config-if)#vlan id 100
   
6. Configure a subscriber (client) bridge group interface over the VLAN subinterface. Assign the interface to the bridge group you created in Step 1.
   host1(config-subif)#bridge-group westford02
   
7. Exit Subinterface Configuration mode.
   host1(config-subif)#exit
8. (Optional) Configure additional VLAN subinterfaces and bridge group interfaces by repeating Steps 4 through 6, supplying unique values.