Feature Example

The following example shows VLAN 20, VLAN 55, and VLAN 103 mapped to bridge groups within a Layer 3 switch (such as a 2948G-L3). Interfaces 1 through 4 on the Layer 3 device are to be mapped to VLAN 20, interfaces 11 and 12 are to be mapped to VLAN 55, and interfaces 25 and 26 are to be mapped to VLAN 103. Interface G 49 will provide the 802.1Q trunk connection to the Layer 2 switch. The switch will also be providing Layer 3 functions for VLAN 55 and VLAN 103. Figure D-1 shows the connections for this example. The configuration that follows would be entered on the Layer 3 switch.

 L3Switch(config)#bridge 20 protocol ieee L3Switch(config)#bridge 55 protocol ieee L3Switch(config)#bridge 103 protocol ieee L3Switch(config)#bridge irb L3Switch(config)#interface Fastethernet 1 L3Switch(interface)#bridge-group 20 L3Switch(interface)#interface Fastethernet 2 L3Switch(interface)#bridge-group 20 L3Switch(interface)#interface Fastethernet 3 L3Switch(interface)#bridge-group 20 L3Switch(interface)#interface Fastethernet 4 L3Switch(interface)#bridge-group 20 L3Switch(interface)#interface Fastethernet 11 L3Switch(interface)#bridge-group 55 L3Switch(interface)#interface Fastethernet 12 L3Switch(interface)#bridge-group 55 L3Switch(interface)#interface Fastethernet 25 L3Switch(interface)#bridge-group 103 L3Switch(interface)#interface Fastethernet 26 L3Switch(interface)#bridge-group 103 L3Switch(interface)#interface Gigabitethernet 49.20 L3Switch(interface-subif)#encapsulation dot1q 20 L3Switch(interface-subif)#bridge-group 20 L3Switch(interface-subif)#interface Gigabitethernet 49.55 L3Switch(interface-subif)#encapsulation dot1q 55 L3Switch(interface-subif)#bridge-group 55 L3Switch(interface-subif)#interface Gigabitethernet 49.103 L3Switch(interface-subif)#encapsulation dot1q 103 L3Switch(interface-subif)#bridge-group 103 L3Switch(interface-subif)#bridge 55 route ip L3Switch(config)#bridge 103 route ip L3Switch(config)#interface BVI 55 L3Switch(interface)#ip address 192.168.55.1 255.255.255.0 L3Switch(config)#interface BVI 103 L3Switch(interface)#ip address 192.168.103.1 255.255.255.0 

Figure D-1. VLAN Extensions