quagga

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

Quagga supports BGP4, BGP4+, OSPFv2, OSPFv3, RIPv1, RIPv2, and RIPng.

Quagga is intended to be used as a Route Server and a Route Reflector. It is not a toolkit, it provides full routing power under a new architecture. Quagga by design has a process for each protocol.