TRACEROUTE / TRACERT


The traceroot command (or tracert on windows) is a software tool used to trace the route taken by data from the local computer to another computer on the internet. As it runs, traceroute displays other routers and gateways that the data passes through along the way to its destination computer. This is invaluable for tracking down and debugging any errors in the route taken by the internet connection to another machine, although like with any tool, it is a double edged sword, since it enables IP addresses of other computers between the local machine and the target machine to be identified.

Traceroute works by sending data packets with a short value called a "Time to Live" (TTL) parameter. Every time a data packet passes through a gateway on the internet, the TTL parameter of the data packet is reduced by 1. When the TTL parameter reaches zero, the gateway that has the packet at that point returns an ICMP "time expired" or ICMP_EXC_TTL message back to the local machine from where it was first sent, thus completing the route.

In terms of troubleshooting, it is when a traceroute command does not reach the machine required / the target machine, that it is then possible to see where in the route the data packet is getting stuck, and thus isolate the problem.

The traceroute command is run either on a domain name or an IP address as follows:

traceroute domain-name or traceroute xxx.xxx.xxx.xxx

Or on a windows based PC:

tracert domain-name or tracert xxx.xxx.xxx.xxx

References



www.cyberthinc.com