To ensure that sites A and B (colocated in the same building) prefer their local LAN for communication over the VPLS connection while still being part of the same VPLS group that includes site C, you can implement a hierarchical VPLS (H-VPLS) setup. This configuration prioritizes local traffic between sites A and B, keeping it on the local LAN, and only routes necessary traffic through the VPLS network to site C.

Local Switch Configuration:

Assume that sites A and B are connected to a local switch:

• Site A: Connected to switch port 1
• Site B: Connected to switch port 2

VLAN Configuration on the Local Switch:

Switch(config)# vlan 10 \\
Switch(config-vlan)# name Local_LAN \\
Switch(config-vlan)# exit \\

Switch(config)# interface GigabitEthernet0/1 \\
Switch(config-if)# switchport mode access \\
Switch(config-if)# switchport access vlan 10 \\
Switch(config-if)# exit \\

Switch(config)# interface GigabitEthernet0/2 \\
Switch(config-if)# switchport mode access \\
Switch(config-if)# switchport access vlan 10 \\
Switch(config-if)# exit

Assuming PE1 and PE2 are the PE routers for sites A and B, and PE3 is for site C:

PE1 and PE2 Configuration:

1. Local Bridge Domain Configuration:

PE1(config)# bridge-domain 100 \\
PE1(config-bdomain)# member GigabitEthernet0/1 service-instance 10 \\
PE1(config-bdomain)# member pseudowire 192.168.1.2 200 \\
PE1(config-bdomain)# exit

1. H-VPLS Configuration for Connecting to Site C:

PE1(config)# bridge-domain 200 \\
PE1(config-bdomain)# member GigabitEthernet0/2 service-instance 20 \\
PE1(config-bdomain)# member pseudowire 192.168.1.3 300 \\
PE1(config-bdomain)# exit

Repeat the configuration on PE2 similarly.

PE3 Configuration (for Site C):

PE3(config)# bridge-domain 200 \\
PE3(config-bdomain)# member GigabitEthernet0/1 service-instance 30 \\
PE3(config-bdomain)# member pseudowire 192.168.1.1 300 \\
PE3(config-bdomain)# member pseudowire 192.168.1.2 300 \\
PE3(config-bdomain)# exit

• Local LAN Configuration: Ensure sites A and B are connected via the local switch and are part of the same VLAN.
• H-VPLS Configuration: Use hierarchical VPLS to handle local traffic within the same building and separate it from the traffic going through the VPLS network to site C.
• Bridge Domains and Pseudowires: Properly configure bridge domains and pseudowires to prioritize local traffic between sites A and B.

This setup ensures that local traffic between sites A and B is switched locally on the LAN, avoiding the VPLS network, while traffic to site C uses the VPLS connection.