[121688] in North American Network Operators' Group
Re: Using /126 for IPv6 router links
daemon@ATHENA.MIT.EDU (Rubens Kuhl)
Sun Jan 24 21:22:00 2010
In-Reply-To: <44D9B071-0987-45D2-8373-B8D70B41DF41@cs.columbia.edu>
Date: Mon, 25 Jan 2010 00:21:51 -0200
From: Rubens Kuhl <rubensk@gmail.com>
To: Steven Bellovin <smb@cs.columbia.edu>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
> During the days of the IPng directorate, quite a number of different alte=
rnatives were considered. =A0At one point, there was a compromise proposal =
known as the "Big 10" design, because it was propounded at the Big Ten Conf=
erence Center near O'Hare. =A0One feature of it was addresses of length 64,=
128, 192, or 256 bits, determined by the high-order two bits. =A0That deal=
fell apart for reasons I no longer remember; SIPP was the heir apparent at=
that point. =A0Scott and I pushed back, saying that 64 bits was too few to=
allow for both growth and for innovative uses of the address. =A0We offere=
d 128 bits as a compromise; it was accepted, albeit grudgingly. =A0The stat=
eless autoconfig design came later.
>
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0--Steve Bellovin, http://www.cs.columbia.e=
du/~smb
This historical record finally made me understand why we have up to
/128 prefixes with /128 addresses instead of what would suit best
stateless autoconfig: up to /64 prefixes with /128 addresses.
Rubens
