EtherApe is a free and open source network traffic monitoring tool for Linux. This packet sniffer application shows network activity graphically. Using this tool you can filter traffic, read packets from a file and live from the network. It is released under GNU General Public License. It comes with link layer, IP and TCP modes and fancy color coded protocols display. It is a fork of a popular etherman app. It supports Ethernet, FDDI, Token Ring, ISDN, PPP, SLIP and WLAN devices.