OSPFv3 uses the same basic implementation mechanism as OSPFv2 but is incompatible with OSPFv2.
Open Shortest Path First (OSPF) is a link-state Interior Gateway Protocol (IGP) developed by the Internet Engineering Task Force (IETF).
OSPF version 2 (OSPFv2) is intended for IPv4, and OSPF version 3 (OSPFv3) is intended for IPv6.
OSPFv3 is an extension of OSPF for support of IPv6.