Traceroute is a utility that allows us to
determine the route data packets take to get to a particular host.
Similar to the ping utility which shows us
the overall time taken to reach the host, traceroute breaks this
process down further by showing us the statistics of each hop
the packets go through.
It works by increasing the TTL (time to live)
value of the packets and recording the time taken to reach each
hop until the final destination is reached.
There are various programs available that
will perform a traceroute for you, but one of the most commonly
used is that provided as part of your operating system.
Windows has a DOS based utility called tracert
that allows us to check and troubleshoot connections, and help
identify any hops which may be causing a problem.
To do this Start >>>
run >>> type "cmd"
Then from the prompt type "tracert [destination]".
Interpreting the results.
to www.bbc.net.uk [212.58.224.113] |
Resolves the host name to
an IP no |
over a max of 30 hops |
By default the no of hops is set to
30.
This can be changed by using the -h command.
eg "tracert -h 20 www.bbc.co.uk |
1 <1 ms router |
Time in milliseconds to reach the
first hop.
In this example it shows it has taken less than 1 millisecond
to reach my router. |
2 23ms 24ms 25ms |
By default 3 packets are sent, so we
can see an average by (23 + 24 + 25) / 3 = 24ms |
lo1.plusnet.pth-ag2.plus.net [195.166.128.6] |
195.166.128.6 refers to the IP address
of the next hop.
DNS resolves this address to the name lo1.plusnet.pth-ag2.plus.net.
Using the -d command stops the host names being resolved to
the IP address. |
*ms |
Occasionally you may see "*ms"
displayed.
This means that this hop has timed out, whilst waiting for
a reply.
You could use the -w command to increase the time-out.
e.g. "tracert -w 5000 [host]" to allow replies
within 5 seconds. |
Save your results.
Ive done a tutorial here
on how to save your results and also how to output them to a
text file.
Tracert Commands
syntax -
tracert [options] destination_host
Options |
-d |
|
Do not resolve address to
hostname. |
-h |
max hops |
Sets the maximum no of hops to try
to reach the host. |
-j |
host-list |
Loose source route along host-list.
|
-w |
timeout |
Timeout in milliseconds to wait for
each hop reply. |
|
|
|
Commands |
Ctrl + C |
Stop tracert |
> c:\filename.txt |
Send results to a text file |
|
|
See also the software
section for tracert tools
|