Chapter 9. OSPFv3

This chapter covers the following subjects:

• Operation of OSPFv3

• Configuring OSPFv3

• Troubleshooting OSPFv3

As you have seen in previous chapters, routing IPv6 requires modifications to a protocol; primarily, the protocol messages must be modified to carry addresses four times as long as IPv4 addresses. In theory, this also could be done with Open Shortest Path First (OSPF), either by modifying the existing Link State Advertisements (LSA) or by defining new LSAs. But development of OSPF began in the very late 1980s, when router performance was low, latency was high, and memory was expensive. None of these are valid now, and several characteristics of OSPFv2 that were intended to accommodate or compensate for those early networking realities are now irrelevant. Further, extensive operational experience with OSPFv2 revealed several areas of inefficiency.

So when extension of OSPF to support IPv6 was first considered, it was recognized that there was an opportunity to improve the protocol itself. The result is that rather than just extending OSPFv2 for IPv6, a new and improved version of OSPFOSPF version 3has been created.