The OSPF VRF Domain ID

If the OSPF instances of an OSPF domain are given one or more domain IDs, OSPF can determine whether an OSPF-originated VPN-IPv4 route belongs to the same domain as a given OSPF instance and whether the route should be redistributed to that OSPF instance as an inter-area route or as an OSPF AS-external route.

If two OSPF instances with a domain ID configured are in the same OSPF domain, the PE-CE protocol requires that the primary domain ID of the second instance must be one of the domain IDs of the first instance (either primary or secondary). If two OSPF instances with a domain ID configured are not in the same OSPF domain, the primary domain ID of each instance must not be configured as a domain ID of the other OSPF instance.

The PE-CE protocol must be enabled using the enable-pe-ce command to set the OSPF VRF domain ID.

Use the domain-id command in OSPF configuration mode to set the domain ID for this PE router.