Wednesday, September 9, 2009

Multi-VRF OSPF router becomes ABR automatically, even when it is not

Once I enabled vrf-aware OSPF (e.g. Router OSPF 1 vrf TEST), it made the router an Area Border Router, even though it was simply an area router (area 1) and didn't have a network statement for area 0.

Remote_R3#sh ip ospf 1
Routing Process "ospf 1" with ID
Domain ID type 0x0005, value
Start time: 00:17:34.712, Time elapsed: 00:26:21.840
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
Connected to MPLS VPN Superbackbone, VRF TEST
It is an area border router
<--- cut off -->

As a result, none of my area 1 routers were accepting routes to the backbone subnet from the real ABRs (configured for area 0 and area 1).

To resolve it, I have to apply "capability vrf-lite" under the OSPF router process on all my area 1 vrf-aware routers. This command tell the router not to perform PE specific check.

No comments:

Post a Comment