Discovering your network with Netdisco
Four years ago, Max Baker at the University of California, Santa Cruz, needed an easy-to-use tool that would assist in managing switch ports, show port usage and history, track inventory, and help with network debugging. Baker began developing what has become Netdisco, an awesome open source network discovery tool.
Netdisco is built on open source packages such as Perl, various Perl modules, Net-SNMP, PostgreSQL, Mason, Apache, and mod_perl. One of its key components is the SNMP::Info Perl module, which Baker also wrote. See the project's requirements page for other modules Netdisco requires to run properly.
Installing Netdisco is not a trivial task. Even for the most seasoned Unix/Linux admin, a manual install can take a number of hours to complete. If you don't want to attempt a manual installation, you can find install scripts for various Linux distributions on the Netdisco mailing list. Netdisco is also included in the NetBSD package system pkgsrc.
After Netdisco is installed and configured, it must discover your network.