Netdisco is an Open Source web-based network management tool.

Designed for moderate to large networks, configuration information and
connection data for network devices are retrieved and set by SNMP. With
Netdisco you can locate the switch port of an end-user system by IP or
MAC address. Data is stored using a SQL database for scalability and
speed.

Cisco Discovery Protocol (CDP), Foundry Discovery Protocol (FDP), and
SynOptics Network Management Protocol (SONMP) optionally provide
automatic discovery of the network topology.

The network is inventoried by both device model and operating system
(like IOS). Netdisco uses router ARP tables and L2 switch MAC forwarding
tables to locate nodes on physical ports and track them by their IP
addresses.

For each node, a time stamped history of the ports it has visited and
the IP addresses it has used is maintained. Netdisco gets all its data,
including topology information, with SNMP polls and DNS queries. It does
not use CLI access and has no need for privilege passwords. Security
features include a wire-side Wireless Access Point (AP) locator.

WWW: http://www.netdisco.org/