BCPs are stable identifiers for Best Current Practices. A BCP may consist of a single RFC or a group of RFCs related to a specific IETF process or recommended guidelines. The collection may become empty as the BCP evolves.
RFC 7608: BCP 198: IPv6 Prefix Length Recommendation for Forwarding
Best Current Practice
- M. Boucadair
- A. Petrescu
- F. Baker
- July 2015
- IETF publication
- Operations and Management Area
Abstract
IPv6 prefix length, as in IPv4, is a parameter conveyed and used in IPv6 routing and forwarding processes in accordance with the Classless Inter-domain Routing (CIDR) architecture. The length of an IPv6 prefix may be any number from zero to 128, although subnets using stateless address autoconfiguration (SLAAC) for address allocation conventionally use a /64 prefix. Hardware and software implementations of routing and forwarding should therefore impose no rules on prefix length, but implement longest-match-first on prefixes of any valid length.
Abstract
IPv6 prefix length, as in IPv4, is a parameter conveyed and used in IPv6 routing and forwarding processes in accordance with the Classless Inter-domain Routing (CIDR) architecture. The length of an IPv6 prefix may be any number from zero to 128, although subnets using stateless address autoconfiguration (SLAAC) for address allocation conventionally use a /64 prefix. Hardware and software implementations of routing and forwarding should therefore impose no rules on prefix length, but implement longest-match-first on prefixes of any valid length.