what is a traceroute application?

To put it in laymen terms it basically traces the route to the host you specify.It will print the addresses of the routers that it encounters between your computer and the destination host. for example in windows if you want to trace the route to let's say www.citibank.com you can type tracert www.citibank.com .

What is the use of this command ?

The traceroute command is a very helpful command in various cases for example you may want to verify the origin address of a spam mail and the route to the origin of mail and determine whether the mail was sent from a valid address or a fake address. In all these cases traceroute application is handy.
Here i will not mention the harmful ways in which the command can be used for breaking into the systems .

How to use the command ?

The output, results and functioning of command remain same in both unix and windows but they have different syntax and options for invoking the application.

Syntax in windows:-

Usage: tracert [-d] [-h maximum_hops] [-j host-list] [-w timeout] target_name

-d Do not resolve addresses to hostnames.
-h maximum_hops Maximum number of hops to search for target.
-j host-list Loose source route along host-list.
-w timeout Wait timeout milliseconds for each reply.

here target_name is the name of the destination host.

For example: tracert -h 16 www.citibank.com

Syntax in unix based systems
: traceroute <hostname|ip address>. Here the difference is in the syntax.To know more options about the command type man traceroute in the command line shell.

What to make of the output ?

Lets say you type traceroute www.citibank.com and the output is like the following:
(please enlarge view the image in a separate window/Tab).

Here everything looks fine except the * * * * in the output. Now what this * in the output simply means is that the router you are accessing is behind a firewall and so you do not see the details of the hostname and ip addresse of that router . But we can always find an alternate path to the host or we can try and exploit the host just prior to the one being blocked by firewall.

That just provides you with sufficient information about how to use the command.

Do post your comments or share this article if you find it helpful.