Brdige domains on Cisco IOS-XE
I was recently tasked to set up a layer 2 cross connect to another city from a HQ to another branch. The ISP gave 2 interconnects on each end that connect to two physical routers on their side but provide the same layer 2 service on a vlan. We only had 1 cisco ASR router on either end. My idea was to bridge the two interfaces into a single bridge and switch across to the other city. Simple task, but I did not realize that the routers i had to work with was IOS-XE. I have not worked on IOS-XE yet.
The configuration for this scenario used to be something like this:
bridge 1 protocol ieee
bridge 1 route ip
!
interface GigabitEthernet0/1.999
encapsulation dot1q 999
bridge-group 1
!
interface GigabitEthernet0/2.999
encapsulation dot1q 999
bridge-group 1
!
interface BVI 1
ip address 1.1.1.1 255.255.255.252
!
This configuration has now changed. Took me almost an hour to figure it out. Configuration for bridge domain and sub interfaces on cisco ASR running ios-xe:
bridge irb
!
interface Gig0/1
no ip address
negotiation auto
service instance 999 ethernet
encapsulation dot1q 999
bridge-domain 999
!
interface Gig0/2
no ip address
negotiation auto
service instance 999 ethernet
encapsulation dot1q 999
bridge-domain 999
!
interface BDI1
ip address 1.1.1.1 255.255.255.252
AS you can see, its the same idea and you get the same result, its just put together differently.