The task of network management is becoming increasingly complex due to the increasing number of networked computers running different operating systems and speaking various network protocols. Most of network monitoring and diagnostic tools such as ping and traceroute are suitable just for tackling simple connectivity problems. Complex network problems often need to be addressed using rather expensive management tools or probes affordable only by mid- to large-sized companies.

This paper covers the design and the implementation of ntop, an open-source Web-based network usage monitor that enables users to track relevant network activities including network utilization, established connections, network protocol usage and traffic classification. Ntop's portability across various platforms, its support of many network media, ease of use and lightweight CPU utilization makes it suitable for people who want to monitor their network without having to adopt a sophisticated yet expensive management platform.