Hello Anoop
The error that you are getting has to do with the way in which OSPF advertises loopback networks. OSPF will always advertise loopbacks as /32 networks, even if you have configured them to be /24. This is how OSPF operates, and it is even defined within RFC 2328. You can see this from the prefixes in the BGP tables on R2 and R5.
If you want to change this behaviour, you can use the ip ospf network point-to-point command under the loopback interface configuration mode. Or you can change the subnet mask on the IP addresses of your loopbacks to eliminate the error.
This error should have no effect on the operation of your MPLS network.
Now the problem you’re facing seems to be coming from your redistribution. Remember, that in the R2 and R5 routers, which are the PE routers in your topology, you have BGP routing, and you have two OSPF processes. You must ensure that redistribution is taking place between the appropriate routing domains. In the lesson, you can see that redistribution is taking place:
- from BGP to OSPF process 2
- from OSPF process 2 to BGP
In your topology, you are also redistributing OSPF 1 into OSPF 2. I suggest you go over the lab again and ensure that you are adhering to the configurations found there. Try it out and let us know how you come along.
I hope this has been helpful!
Laz