What are the causes for a GRE tunnel establishment failure

The causes for a GRE tunnel establishment failure are as follows:

-Interfaces on both ends of a tunnel use different tunnel encapsulation modes.
-An IP address, a tunnel source address, and a tunnel destination address are not configured for interfaces on both ends of the tunnel. The source address of one end is not the destination address of the other end.
-There is no reachable route between the tunnel source and destination addresses.
-Keepalive detection is configured, but parameters on both ends of a tunnel are inconsistent.
-GRE key configurations on both ends of a tunnel are inconsistent.

Scroll to top