How to turn your CentOS box into an OSPF router using Quagga

Quagga is an open source routing software suite that can be used to turn your Linux box into a fully-fledged router that supports major routing protocols like RIP, OSPF, BGP or ISIS router. It has full provisions for IPv4 and IPv6, and supports route/prefix filtering. Quagga can be a life saver in case your production router is down, and you don’t have a spare one at your disposal.