SysAdminGear

"ntop is a network probe that shows network usage in a way similar to what top does for processes. In interactive mode, it displays the network status on the user's terminal. In Web mode, it acts as a Web server, creating an HTML dump of the network status. It sports a NetFlow/sFlow emitter/collector, an HTTP-based client interface for creating ntop-centric monitoring applications, and RRD for persistently storing traffic statistics.
ntop is available for both Unix and Win32-based platforms. It has been developed by Luca Deri, an Italian research scientist and network manager at University of Pisa."
( http://en.wikipedia.org/wiki/Ntop )

Related Links:
ntop homepage
ntop wiki


Ntop monitors these protocols:
TCP/UDP/ICMP
IPX
Decnet
AppleTalk
NETBIOS
TCP/UDP

Links
http://dag.wieers.com/rpm/packages/ntop
http://rpmfind.net/linux/RPM/fedora/4/i386/glib-1.2.10-16.i386.html

Installation Procedure:

Install G-LIB:
# rpm -ivh glib-1.2.10-16.i386.rpm

Install ntop:
# rpm -ivh ntop-3.2-1.el4.rf.i386.rpm

Run ntop:
# ntop
The default username: admin / Password: yourEnteredpassword

Start ntop service:
# service ntop start

Web Interface:
ntop can be managed through a web interface:
http://serveripaddress:3000
https://serveripaddress:3001

It should be fine now..