Mixed - Version IP Router ( MIR )

This application note describes a reference design for a mixed-version IP router (MIR) servicing up to four gigabit Ethernet ports. MIRs are useful where several gigabit Ethernet networks are operating with a mixture of IPv4 and IPv6 hosts and routers attached directly to the networks, and further nodes reached via the routers. A particular benefit of an approach based on the Virtex-II ProTM family is that the router’s functions can evolve smoothly, maintaining router performance as the organization migrates from IPv4 to IPv6 internally, and also as the Internet migrates externally.