I remember being so happy about 0trace when I started to write some Backtrack related articles because even though 0trace is fairly simple it is really useful to locate the full path to devices you are investigating. In the article below I will explain the necessary 0trace input from the command line, what needs to be done to complete a successful trace to a target using 0trace, and provide some example of devices in front of and behind a firewall blocking ICMP or traceroute requests.
Previously I wrote a brief article on 0trace in Backtrack 4 which can be located here however in the process of writing an updated article for Backtrack 5 I noticed that 0trace was no longer working. Every single time I would attempt to run an accurate trace through a firewall the results would come back empty and display “Probe rejected by target.” At first I was thinking maybe companies have really tightened down their firewalls however that didn’t make any sense because of how 0trace works using a standard port such as port 80 to allow traffic to pass because the servers function is to serve web pages. Below I describe the error in more detail and how you can resolve it.