GNU Zebra is free software that manages TCP/IP based routing protocols.
It takes a multi-server and multi-thread approach to resolve the current
complexity of Internet routing.

GNU Zebra supports BGP4, BGP4+, OSPFv2, OSPFv3, RIPv1, RIPv2, and RIPng.

GNU Zebra also supports Route Server and a Route Reflector.  It provides
full routing power under a new architecture.  GNU Zebra is unique in
design in that it has a process for each protocol.