Chapter 8 Configuring Ethernet Virtual Connections

Configuring Other Features on EFPs

encapsulation dot1q 20 second-dot1q 30 rewrite ingress tag pop 2 symmetric bridge-domain 101

int vlan 101

ip address 2.2.2.2 255.255.255.0

In the above example:

The traffic coming from the Base Transceiver Station (BTS) through the GigabitEthernet interface 0/1 has the VLAN tag 10, which is popped and hits the Switch Virtual Interface (SVI) 100.This gets routed to SVI 101 depending on the destination address.

At the egress on the core interface, two tags (20 and 30) are pushed and sent out of GigabitEthernet interface 0/2, for SVI 101.

The traffic coming from the core router through GigabitEthernet interface 0/2, is destined to the BTS and has two tags (20,30); both tags get popped and hit SVI 101. This gets routed to SVI 100, which sends the traffic out of GigabitEthernet interface 0/1 with VLAN 10.

GigabitEthernet interface 0/2 can have multiple service instances and the traffic egresses out of the corresponding service instance depending on the SVI it gets routed to.

Bridge Domain Routing

The router supports IP routing for bridge domains, including Layer 3 and Layer 2 VPNs, using the SVI model.

Restrictions

You must configure SVIs for bridge-domain routing.

The bridge domain must be in the range of 1 to 4094 to match the supported VLAN range.

There can be only one EFP in the bridge domain.

You cannot have any Layer 2 switchports in the VLAN (bridge domain) used for routing.

You can use bridge domain routing with only native packets.

MPLS is supported on EFP with SVI.

Scale limit for EFPs reduces if you use the second-dotlqcommand. Use the second-dotlq any command to maintain this limit.

Example: Configuring Bridge-Domain Routing

This is an example of configuring bridge-domain routing with a single tag EFP:

Router (config)# interface gigabitethernet0/2

Router (config-if)#service instance 1 Ethernet

Router (config-if-srv)# encapsulation dot1q 10

Router (config-if-srv)#rewrite ingress tag pop 1 symmetric

Router (config-if-srv)# bridge-domain 100

Router (config)# interface vlan 100

Router (config-if)#ip address 20.1.1.1 255.255.255.255

 

Cisco ASR 901 Series Aggregation Services Router Software Configuration Guide

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Cisco Systems A9014CFD manual Bridge Domain Routing, Example Configuring Bridge-Domain Routing