OSPFv3 Instance ID Registry Update
updates
- rfc-5838 — Support of Address Families in OSPFv3
Extracted elements (5)
A Private Use range (192-255) was carved out of the previously fully-Unassigned 128-255 block to allow operators to locally assign Instance IDs for specific applications without requiring IANA coordination. The motivating use case is IPv4-embedded IPv6 routing (as in draft OSPF-EMBED), where a separate Instance ID space enables easy operational identification of the application.
Assignment of OSPFv3 Instance ID values from the Unassigned range 128-191 requires Standards Action as defined by RFC 5226.
OSPFv3 Instance IDs are 8-bit values (0-255) mapped to address families. RFC 5838 originally defined: 0 (IPv6 unicast), 1-31 (IPv6 unicast policy-dependent), 32 (IPv6 multicast base), 33-63 (IPv6 multicast policy-dependent), 64 (IPv4 unicast base), 65-95 (IPv4 unicast policy-dependent), 96 (IPv4 multicast base), 97-127 (IPv4 multicast policy-dependent), and 128-255 (Unassigned).
The IANA 'OSPFv3 Instance ID Address Family Values' registry is updated by RFC 6969: Instance IDs 128-191 remain Unassigned but now require Standards Action for assignment, while Instance IDs 192-255 are designated Reserved for Private Use per RFC 5226. The previous RFC 5838 reference is removed for these modified ranges.
RFC 6969 modifies only an IANA registry and introduces no new security issues beyond those already present in RFC 5838.