BGP Extended Communities for OSPF PE-CE Routing-domain ID analysis

BGP Extended Communities for OSPF PE-CE Routing-domain ID analysis to make OSPF Routing characteristics can pass through the mpls vpn backbone network, it needs to define some BGP Extended group attributes. OSPF attributes that can be passed through mp bgp include:

The extended attribute of mp bgp allows OSPF routes to be completely rebuilt on the remote PE router. The lsa type allows the remote PE router to know what TYPE of routing is advertised in OSPF. If LSA = 1, LSA = 2, and LSA = 3, the remote PE will advertise a summary route (LSA Type 3) to the OSPF region. Domain id indicates whether the remote PE router is an external OSPF route. If the domian id received by the pe router (OSPF process ID by default) cannot match the OSPF process ID of a specific VRF, this route will be advertised in the form of an OSPF external route (LSA = 5) and metric Value Type 2. To support the redistribution of IP routing between different OSPF processes in the network. If yes, advertise the internal route. You can change the domain id command to domain-id domain id.
If the option field is set, the external measurement value is type 2. If this parameter is not set, the external metric value is type 1. Verification: For the configuration, see add www.2cto.com.
View 1.1.1.1/32 on R5 (L0 of R1)

On R6, because the domain id does not match the VRF, it will exist as an external route.
If domian id = 52 is set on R

Check 1.1.1.1/32 on R5.
It is found that the vrf ospf process of domain id = 52 and R5 should be an internal route (LSA = 3) verified on R6.

Author: wenlf136