OSPF Domain ID in MPLS

OSPF Domain ID Role in MPLS

When OSPF is used as the routing protocol on a MPLS Provider Edge to customer edge (PE-CE) link in (MPLS) VPN. PE routers mark OSPF routes with the domain attribute derived from the OSPF process number, it indicates whether the route originated within the same OSPF domain or from other OSPF domain. If the OSPF process numbering is inconsistent on PE routers in the MPLS VPN, the domain-id command in OSPF should be used to mark that the OSPF processes with different numbers belong to the same OSPF domain.

Then you can get O IA routes instead of E2 routes.

The command are :

Show ip ospf  ( To know the domain id)

PE-1#sh ip ospf 2

 Routing Process "ospf 2" with ID 200.1.1.1

   Domain ID type 0x0005, value 0.0.0.2  (Check the value field).

 router ospf  
domain-id 0.0.0.x

Then check the OSPF route type it will be O IA.