Hello All,

I am fairly new to using traceroute. I work on a project where multiple clients send messages to one server via TCP/IP (programs are written in C). The network path between those clients and the server varies by client. In many instances, I am seeing 0 bytes read on the socket from a particular client. E.g, there is a lot of data getting lost (not received by the server).

In trying to debug, I have been using traceoute (traceoute -T). In many of the cases, I am seeing traceroute complete (successfully?) at a different IP then the one that I specified. In fact, for most of those client destinations, traceroute completes at the same IP. There is some delay and a few asterisks are displayed before traceroute finishes.

So, if I am running a traceroute -T from 111.222.333.444 to 555.777.888.999 I would see output something like

1. 111.222.333.444 x ms
2. 3.44.55.66 xms
..........
10. 555.444.333.22 *

that same IP (in this case, 555.444.333.22) is the last hop shown for any of the clients I am trying to run the traceroute to. Is this an indication of a problem? Or am I misunderstanding the output of traceroute?

I appreciate any input.

thanks,
Bill

You are not reaching the server you want. If the whole network involved is inside your organisation someone there should be able to solve it by adding routes somewhere.

Thank you for the response. I also noticed something just now towards the end of the traceroute output. Right before printing that last IP I see an '!X'. According to documentation this means 'Communication Administratively Prohibited'. Does this mean I am being blocked at a firewall somewhere prior to reaching my intended destination? If that is the case, what other options do I have? I noticed in documentation that I can specify a port number (80 is the default I believe). Any ideas appreciated.

thanks,
Bill

I followed up on my last post and tried running a traceroute to a specific 'port number'. In that particular case, I got through to the destination. When I used the default port number (e.g., ran traceroute without the '-p' option) the trace stopped before reaching the destination. The only thing I can deduce from this is that I hit some router somewhere that disallowed traffic on the default port??????

thanks,
Bill