Netdot is an open source tool designed to help network administrators collect, organize and maintain network documentation.
Netdot was initially developed by the Network Services group at the University of Oregon, and continues to be maintained and expanded with support from the Network Startup Resource Center and the work of volunteers.
Relevant features:
  • Device discovery via SNMP
  • Layer2 topology discovery and graphing, using:
    • CDP/LLDP
    • Spanning Tree Protocol
    • Switch forwarding tables
    • Router point-to-point subnets
  • IPv4 and IPv6 address space management (IPAM)
    • Address space visualization
    • DNS/DHCP config management
    • IP and MAC address tracking
    • BGP peer and Autonomous Systems tracking
  • Cable plant (sites, fiber, copper, closets, circuits...)
  • Contacts (departments, providers, vendors, etc.)
  • Export scripts for various tools (Nagios, Sysmon, RANCID, Cacti, SmokePing)
  • Multi-level user access: Admin, Operator, User
Access the tool here.