client=====[router1]====[router2]====[router3]=====[router4-gre/tunnel ]===[gre/tunnel router5]===server
What is the best way to troubleshoot/identify which router in this path is blocking a udp response from the server to the client?
I am able to get anything that is TCP back to the client but strangely enough UDP traffic isn't reaching my client. How does one find the offending router without logging in to it? Is this possible?