Refer to the exhibit. A network engineer has configured GRE between two IOS routers. The state of the tunnel interface is continuously oscillating between up and down. What is the solution to this problem?
A. Create a more specific static route to define how to reach the remote router.
B. Create a more specific ARP entry to define how to reach the remote router.
C. Save the configuration and reload the router.
D. Check whether the internet service provider link is stable
C
https://www.cisco.com/c/en/us/support/docs/ip/generic-routing-encapsulation-gre/118361-technote-gre-00.html
P2P GRE Tunnel State
Normally, a P2P GRE Tunnel interface comes up as soon as it is configured with a valid tunnel source address or interface which is up and a tunnel destination IP address which is routable as shown in the previous section.
Line Protocol Down Locally on the Router
Under normal circumstances, there are only three reasons for a GRE tunnel to be in the up/down state:
– There is no route, which includes the default route, to the tunnel destination address.
– The interface that anchors the tunnel source is down.
– The route to the tunnel destination address is through the tunnel itself, which results in recursion.
These three rules (missing route, interface down, and misrouted tunnel destination) are problems local to the router at the tunnel endpoints and do not cover problems in the intervening network or other features related to the GRE tunnel that might be configured. This document describes scenarios where other factors might influence the state of the GRE tunnel.
Sorry.
Correct Answer: A