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 Pro™ 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 external. This product is not recommended for new designs.

xapp655.pdf