To allow OSPF route exchange between a CE router and its associated PE router, OSPF must be enabled on the interface that connects to the VRF-enabled interface of its associated PE router. To configure OSPF on the interface of the CE 1 router in OSPF to CE network example that is connected to the VRF VPN1 associated interface on PE 1, enter the following commands.
device(config)# interface ethernet 1/1
device(config-if-e10000-1/1)# ip ospf area 1
device(config-if-e10000-1/1)# ip address 10.33.33.2