The program that we're going to take a look at is called Wireshark. It's an open source packet sniffer with support for interpreting a vast range of network protocols.
For Windows and Linux, Wireshark can be downloaded from http://www.wireshark.org. On Debian, Ubuntu, RHEL, CentOS, and Fedora it's available as the
You'll need to have root or administrator access in order to install this. On Windows, make sure that you install or update the
WinPcap library if it asks you to do so, and also allow it to start the
WinPcap driver at boot time when prompted.
On Debian and Ubuntu, you will need to configure Wireshark to allow regular users to run captures. Run the following command:
$ sudo dpkg-reconfigure wireshark-common ...