After you configure a GRE tunnel between two networks, the tunnel comes up normally, but workstations on each side of the tunnel cannot communicate. Which reason for the problem is most likely true?
A. The tunnel source address is incorrect.
B. The tunnel destination address is incorrect.
C. The route between the networks is undefined.
D. The IP MTU is incorrect.
E. The distance configuration is missing.
A. False – tunnel wouldn’t come up
B. False – tunnel wouldn’t come up
C. True – Endpoints will not be able to communicate without a route
D. False – IP MTU has no affect on tunnel connectivity (tested in GNS3)
E. False – Distance has no effect on tunnel connectivity
Answer is C
Tunnel can be up without matching MTU size
MTU size will only effect the traffic passing through the tunnel.
MTU works differently on Physical interface & Tunnel interface.
i would go with D
D. The IP MTU is incorrect.
I will go with C on this one.
Let’s say the MTU is incorrect, then you also have to adjust the MSS value. Modifying the MTU value does not directly solve the issue. And I have tested in production network that leaving the MTU value to 1500 and configuring the proper routing allow hosts in each side of the tunnel to communicate.
If someone has a better answer or experience kindly correct my statement.
https://community.cisco.com/t5/networking-documents/how-to-configure-a-gre-tunnel/ta-p/3131970/page/2
Ali please don’t misguide people if you are not sure answering this. Proper way to answer is to provide appropriate information explaining the answer. So.. I will try to explain this (especially to you). In the scenario we have a GRE tunnel that is operative and in state UP – meaning all parameters to establish the tunnel including MTU are correct. This removes options A,B and D from answers. Distance is optional parameter that is added to an already working configuration – so this rules this one (E) out. We are left with the correct answer C which makes most sense..
Thank you so much Jani.
come on bra . don b a douche