Perform the following steps to solve this problem:

1.Check whether the interface type of one device is P2P while the interface type of the other device is unnumbered P2P.
2.Check whether the IP address is valid.
3.Check whether the forwarding address is known and reachable.
4.Check whether the routes are summarized or redistributed correctly.
5.Check whether different masks or IP addresses are used in the Peer-to-peer (P2P) connection.
6.Check whether route lists are advertised.
7.Check whether the backbone area is disconnected.

nice solution indeed...

very informative indeed

helpful post.

good job

useful document, thanks

useful document, thanks