etherape
Etherape is a graphical network monitor for Unix modeled after etherman.
Featuring link layer, ip and TCP modes, it displays network activity
graphically. Hosts and links change in size with traffic. Color coded
protocols display. It supports Ethernet, FDDI, Token Ring, ISDN, PPP
and SLIP devices. It can filter traffic to be shown, and can read
traffic from a file as well as live from the network.