With the ever changing landscape of networking, this is a how to about creating a L2VFI (VPLS point to multi-point) on a Cisco ASR 920 Router. This How-To assumes you already have OSPF routing in place, the global mpls commands, and the mpls ip command on your point-to-point OSPF links.
Step 1: Console to the Router
Cisco ASR 920 Routers come with a dongle to serial into the device. Optionally you can use a USB cable to connect. Same basic COM port settings as many Cisco devices. 9600, 8, None, 1. You can use putty or whatever your favorite client is.
Step 2: Enter Configuration Mode
- Enable
- Config T
router (config)#
Step 3: L2VFI Commands
Now that you are in global configuration mode. You need to enter the commands to provision an L2VFI.
Create the bridge-domain (VLAN)
router(config)# bridge-domain <id>
router (config)# l2 vfi <name> manual router(config-vfi)# vpn id <bridge-domain id> router(config-vfi)# bridge-domain <id> router(config-vfi)# neighbor 10.20.30.40 pw-class <Name> no split-horizon. (config-vfi-neighbor)#end
The 10.20.30.40 (Loopback) is the other end of the L2VFI (Core Network) – Same commands if pointing at another Cisco ASR 920. Lets assume we are using a 920 in the core. The neighbor commands on the Core 920 would be vice-versa pointing towards the other routers loopback address (lo0).
Step 4: Verify the VFI is up/down
To verify that the VFI is in a UP or DOWN state run the command below:
show xconnect all | include vfi <Name>
UP pri vfi <Name> UP mpls 10.20.30.40:<VPN ID> UP
If it shows down (DN). Make sure your MTU settings match on each end and OSPF is working between the routers.
To view in detail about the circuit:
show mpls l2transport vc vcid <id> detail
Step 5: Add Service Instances to Switchports
router(config)# interface Gi0/0/0 router(config-if)# service instance <id> ethernet router(config-if)# encapsulation dot1q <id> router(config-if)# rewrite ingress tag pop 1 symmetric router(config-if)# bridge-domain <id>
The above commands would be for a trunked port.
Untagged:
router(config-if)# service instance <id> router(config-if)# encapsulation untagged router(config-if)# bridge-domain <id>
That is all there is to it. Of course this assumes you already have OSPF routing between the routers and global mpls commands and on your p2p ospf links. Happy L2VPN’ing.