OSPFv3 Prefix Information Separation
The OSPF protocol uses LSA types to share network topology information. In OSPFv2, LSA types 1 and 2 include both the prefix information and the SPF (Shortest Path First) tree data, which represents network topology and is recalculated upon receiving these LSAs. This can lead to inefficiencies, as changes in interface IP addresses unnecessarily trigger recalculations even when the SPF tree remains unchanged.
To address these inefficiencies, OSPFv3 separates prefix information from the SPF tree. In this version, types 1 and 2 LSAs contain only SPF tree information, while type 9 LSAs handle prefix updates without triggering SPF recalculations. Consequently, a change in an IP address results in the transmission of a type 9 LSA without recalculating the SPF, thereby improving efficiency. OSPFv3 was initially designed for IPv6 but can also be applied to IPv4 (RFC 5838), benefiting from the same separation advantage.
Links
https://networklessons.com/ipv6/ospfv2-vs-ospfv3