I stand corrected. BTW there is also the issue of interaction with ILNP, which has been recommended to the IETF by the RRG chairs.
Brian On 2011-03-03 10:25, Thomas Narten wrote: >> [RFC4862] requires that subnets operating stateless address >> autoconfiguration use 64 bit prefixes, > > Actually, not true! Stateless address autoconfiguration supports > different prefix lengths just fine. That was a deliberate design > decision, even after we switched to 64-bit Interface IDs. E.g (from > 4862): > > A link-local address is formed by combining the well-known link-local > prefix FE80::0 [RFC4291] (of appropriate length) with an interface > identifier as follows: > > 1. The left-most 'prefix length' bits of the address are those of > the link-local prefix. > > 2. The bits in the address to the right of the link-local prefix are > set to all zeroes. > > 3. If the length of the interface identifier is N bits, the right- > most N bits of the address are replaced by the interface > identifier. > > If the sum of the link-local prefix length and N is larger than 128, > autoconfiguration fails and manual configuration is required. The > length of the interface identifier is defined in a separate link- > type-specific document, which should also be consistent with the > address architecture [RFC4291] (see Section 2). These documents will > carefully define the length so that link-local addresses can be > autoconfigured on the link. > > and so on. > >> and [RFC4291] requires that interface identifiers conform to >> modified EUI-64 format. > > That is where the effective requirement is hard coded in. > > Thomas > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
