Well, my interpretation is that EUI-64s always have the universal/local bit set to universal. And, non-EUI-64's have the universal/local bit "set" to local. For local ones, I assume that the 'c' and 'm' bits are "anything goes". The question then is whether the individual/group bit applies.
If one looks at the anycast addresses, those are group (as well as local). So, that seems to imply that this carries over. But, the following appendix section: Links with Other Kinds of Identifiers There are a number of types of links that have link-layer interface identifiers other than IEEE EUI-64 or IEEE 802 48-bit MACs. Examples include LocalTalk and Arcnet. The method to create a Modified EUI-64 format identifier is to take the link identifier (e.g., the LocalTalk 8-bit node identifier) and zero fill it to the left. For example, a LocalTalk 8-bit node identifier of hexadecimal value 0x4F results in the following interface identifier: |0 1|1 3|3 4|4 6| |0 5|6 1|2 7|8 3| +----------------+----------------+----------------+----------------+ |0000000000000000|0000000000000000|0000000000000000|0000000001001111| +----------------+----------------+----------------+----------------+ Note that this results in the universal/local bit set to "0" to indicate local scope. Does not mention the individual/group bit, just the universal/local. So, it is a bit unclear. - Bernie -----Original Message----- From: Suresh Krishnan [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 28, 2007 2:17 PM To: Bernie Volz (volz) Cc: ipv6@ietf.org Subject: Re: Reserved interface identifier registry Hi Bernie, Bernie Volz (volz) wrote: > 4291 does mention it in Appendix A: > > where "c" is the bits of the assigned company_id, "0" is the value of > the universal/local bit to indicate universal scope, "g" is > individual/group bit, and "m" is the bits of the manufacturer- > selected extension identifier. The IPv6 interface identifier would > be of the form: > > |0 1|1 3|3 4|4 6| > |0 5|6 1|2 7|8 3| > +----------------+----------------+----------------+----------------+ > |cccccc1gcccccccc|ccccccccmmmmmmmm|mmmmmmmmmmmmmmmm|mmmmmmmmmmmmmmmm| > +----------------+----------------+----------------+----------------+ > > The only change is inverting the value of the universal/local bit. It mentions what the format of the EUI-64 is. Not what these bits mean in the IID. My take on this is that the format of the EUI-64 has nothing whatsoever to do with the format of the IID. If this were true we need to get OUIs assigned by IEEE (The 'c' bits in the figure) for each of the random IID generation techniques. Do you agree? Cheers Suresh -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
