ntop is a network traffic probe that shows the network usage, similar to what the popular top Unix command does. ntop is based on libpcap and it has been written in a portable way in order to virtually run on every Unix platform and on Win32 as well.
ntop users can use a a web browser (e.g. netscape) to navigate through ntop (that acts as a web server) traffic information and get a dump of the network status.
What Ntop can do ?
* Sort network traffic according to many protocols
* Show network traffic sorted according to various criteria
* Display traffic statistics
* Store on disk persistent traffic statistics in RRD format
* Identify the identity (e.g. email address) of computer users
* Passively (i.e. without sending probe packets) identify the host OS
* Show IP traffic distribution among the various protocols
* Analyze IP traffic and sort it according to the source/destination
* Display IP Traffic Subnet matrix (who’s talking to who?)
* Report IP protocol usage sorted by protocol type
* Act as a NetFlow/sFlow collector for flows generated by routers (e.g. Cisco and Juniper) or switches (e.g. Foundry Networks)
* Produce RMON-like network traffic statistics
Download :
http://www.ntop.org/download.html