OSPF version 2 (OSPFv2) is used with IPv4. OSPFv3 has been updated for compatibility with IPv6's 128-bit address space. However, this is not the only difference between OSPFv2 and OSPFv3. Other changes in OSPFv3, as defined in RFC 2740, include
* protocol processing per-link not per-subnet
* addition of flooding scope, which may be link-local, area or AS-wide
* removal of opaque LSAs
* support for multiple instances of OSPF per link
* various packet and LSA format changes (including removal of addressing semantics).
Both OSPFv2 and OSPFv3 are fully supported by DC-OSPF.
