On Tue, 9 Nov 2010 19:08:45 +1030 Mark Smith <i...@69706e6720323030352d30312d31340a.nosense.org> wrote:
> Hi Hemant, > > On Mon, 8 Nov 2010 19:11:17 -0600 > "Hemant Singh (shemant)" <shem...@cisco.com> wrote: > > > Mark, > > > > -----Original Message----- > > From: ipv6-boun...@ietf.org [mailto:ipv6-boun...@ietf.org] On Behalf Of > > Mark Smith > > Sent: Monday, November 08, 2010 5:12 AM > > To: Thomas Narten > > Cc: ipv6@ietf.org > > Subject: Re: draft-ietf-6man-prefixlen-p2p-00.txt > > > > > > >I think the Addressing Architecture RFC would need to be changed, as it > > >stipulates 64 bit interface ids, which I think implies a maximum of 64 > > >bit prefix lengths, unless these /127s were only permitted within 0::/3 > > >- the impacted text is in 2.5.1 of RFC4291 - > > > > >"For all unicast addresses, except those that start with the binary > > > value 000, Interface IDs are required to be 64 bits long and to be > > > constructed in Modified EUI-64 format." > > > > Why should any text in RFC 4291 change? The IID for /127 starts with > > binary 000 and only the Modified EUI-64 format has got to deal with the > > u/g bits. > > > > I'm pretty sure the leading three 000s referred to are at the start > of the unicast IPv6 address, not at the start of the IID portion. > > My assumption has been that this 000s exception is what has > allowed allowed unicast ::1 to be a /128. I think ::1/64 would comply > with the Modified EUI-64 requirement, so the only reason for the > exception that I can think of is to allow the prefix length of ::1 > to be /128 instead of /64. > > (In the past I've had some uses for multiple loopback addresses within > IPv4 127/8, so I actually wouldn't have minded ::/64 being a loopback > network/subnet, with ::1 the first default IID value for loopback, but > other loopback IIDs allowed. IIRC, ntpd also uses addresses within IPv4 > 127/4 to represent different local time sources on the local host) ^^^^^ oops .. 127/8 > Regards, > Mark. -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
