Troubleshooting and Maintaining Cisco IP Networks (TSHOOT, legacy) — Question 33

A syslog message from a router with a GRE tunnel reads: "%TUN-5-RECURDOWN: Tunnel0 temporarily disabled due to recursive routing". Which scenario would cause this error?

Answer options

• A. The remote router's tunnel interface is not participating in the routing process.
• B. The local tunnel mode does not match the tunnel mode configured on the remote router.
• C. The shutdown command has been issued on the source physical interface.
• D. The installed route to the tunnel destination has been learned via the tunnel interface. D

Correct answer:

Explanation

The correct answer is D because if the route to the tunnel destination is learned via the tunnel interface, it creates a recursive routing scenario, causing the tunnel to be disabled. Options A, B, and C do not directly relate to recursive routing, as they address issues with routing participation, mode mismatch, and interface status respectively.