Cisco Support Community
Community Member

connection problem


We have a client who seems to have a strange connection problem connecting to our network. Traceroute drops at our router whenever he does traceroute to our network, but we have not set any ACL to block this client. Here is more strange things.

Traceroute fialed if the source ips are orginated at client's LAN or Qwest router(x.x.96.73), however it gets to our network from client's router( without any problem.

Client LAN(x.x.101.32/27)



Client's router(x.x.96.74/30)



Client's next hop/Qwest router(x.x.96.73/30)






Our router

Any suggestion or a comment would greatly appreciated...

Thank you

Community Member

Re: connection problem

Does the client have a F/W? Just because it *looks* like your router is dropping the traces doesn't mean he actually is.

Could your next hop router being dropping the packet, does he have a full route table?

If you see your router in the trace route that means he was the last one that DID know about the path to return the echo. Problem could be with your next hop router not knowing the path to return the echo.

If you do a SHO IP ROUTE on your router (and your next hop router) for the client LAN is it pointing back in the same direction?

You mention the client router (96.74) works but the Qwest router (96.73) doesn't. Are you doing extended pings on the qwest? by default, from your drawing above the qwest wouldn't be sourcing from 96.73, that is the backside interface. Qwest would by default send the forward facing interface, is that interfaces IP in your route table?


Community Member

Re: connection problem


Thanks for your writing.

Unfortunately, I have no idea how the network like in client's side since I don't access to it... :(

I made the diagram based on their emails with traceroute results.

Route table looks ok on our side.....route is pointing at the right direction. :)

CreatePlease to create content