The change from IPv4 to IPv6 is not just about one protocol being replaced by another; it impacts many other protocols as well. In this super-sized chapter, we start by introducing IPv6 addressing and routing, also discussing troubleshooting of the same. We then cover OSPFv3 (Open Shortest Path First Version 3) and EIGRPv6 (Enhanced Interior Gateway Routing Protocol for IPv6), in detail.