route type for ospf routes over MPLS, E2 or IA ?

[gongya001]

PE-2
ip vrf CustA
 rd 1256:12
 route-target export 1256:16
 route-target import 1256:16

router ospf 12 vrf CustA
 redistribute bgp 65100 subnets
 network 192.168.12.0 0.0.0.15 area 0

router bgp 65100
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 5.5.5.5 remote-as 65100
 neighbor 5.5.5.5 update-source Loopback0
 !
 address-family ipv4
 exit-address-family
 !
 address-family vpnv4
  neighbor 5.5.5.5 activate
  neighbor 5.5.5.5 send-community both
 exit-address-family
 !
 address-family ipv4 vrf CustA
  redistribute ospf 12
 exit-address-family

PE5
ip vrf CustA
 rd 1256:56
 route-target export 1256:16
 route-target import 1256:16

router ospf 56 vrf CustA
 redistribute bgp 65100 subnets
 network 192.168.56.0 0.0.0.15 area 0

router bgp 65100
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 2.2.2.2 remote-as 65100
 neighbor 2.2.2.2 update-source Loopback0
 !
 address-family ipv4
 exit-address-family
 !
 address-family vpnv4
  neighbor 2.2.2.2 activate
  neighbor 2.2.2.2 send-community extended
 exit-address-family
 !
 address-family ipv4 vrf CustA
  redistribute ospf 56
 exit-address-family

PE-2#show ip route vrf CustA ospf | b Gate
Gateway of last resort is not set

      1.0.0.0/32 is subnetted, 1 subnets
O        1.1.1.1 [110/11] via 192.168.12.1, 00:32:17, Ethernet0/0
      11.0.0.0/32 is subnetted, 1 subnets
O        11.11.11.11 [110/11] via 192.168.12.1, 00:32:17, Ethernet0/0

CE-6#show ip route ospf | b Gateway
Gateway of last resort is not set

      1.0.0.0/32 is subnetted, 1 subnets
O E2     1.1.1.1 [110/11] via 192.168.56.5, 00:11:25, Ethernet0/0
      192.168.12.0/28 is subnetted, 1 subnets
O E2     192.168.12.0 [110/1] via 192.168.56.5, 00:11:25, Ethernet0/0

CE-6 is behind PE5, 1.1.1.1 and 192.168.12.0/28 are behind PE2.

These two routes go from CE1 to CE6 over MPLS, should they be IA or E2 ?

The above is from my lab, but the video I am watching showing IA.

thanks !!

[balaji.bandi]

it should be IA routes since they belong to same Customer.

High level -  Why you have different OSPF processes running?  Do you run the same OSPF process on both the side - correct and test

[gongya001]

fixed.

thanks a lot !!!!

[gongya001]

thanks, it fixed.

[balaji.bandi]

Glad that all working as expected.

[gongya001]

I found I missed the following points:

• By default process id is used as the domain ID on IOS.
• Domain ID controls if OSPF routes are imported from MPLS super area as LSA 3 or LSA 5.
• RFC 4577 establishes that as long as OSPF routers are in the same domain-id they should be able to import routes from BGP as LSA type 3 (network summary). If they are not in the same domain id, routes will be imported as external LSAs.

[balaji.bandi]

if you like to have different OSPF processes - you can also use domain option on the PE side, so they will be announced the same LSA.

use case like if 2 companies merge and like to keep the existing config on the PE side. 

[gongya001]

Thanks!