nanog mailing list archives
Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks?
From: Bill Stewart <nonobvious () gmail com>
Date: Wed, 30 Nov 2011 15:02:09 -0800
On Wed, Nov 30, 2011 at 1:18 PM, Mark Blackman <mark () exonetric com> wrote:
... and I'm not sure why SLAAC wanted more than 48 bits.
One reason IPv6 addresses are 128 bits long instead of 40, 48, 64 or 80 is because converting from IPv4 to IPv6 is really painful and we don't want to ever have to do it again in the future. Eventually we will run out of 48-bit MAC addresses, because we'll run out of 24-bit manufacturer ID parts, and we'll transition to EUI-64 or something like it. It will be ugly and painful, and it will break many things, and if we used 48-bit MAC addresses for SLAAC, it would break IPv6 as well. Using EUI-64 instead of MAC means that all the breakage will live at Layer 2. It does break some things in IPv6 - we've spent a couple of years arguing about whether ISPs should give customers /48, /56, /60, or /64, instead of having the nice clean "64 bits for the network provider, 16 bits for subnet, 48 for MAC" that the earlier proposals adapted from Netware IPX, but that would probably have gotten us in trouble also. I can't explain why EUI-64 picked its particular ugly way to convert 48-bit MACs to 64-bit, but I won't rant about that here. -- ---- Thanks; Bill Note that this isn't my regular email account - It's still experimental so far. And Google probably logs and indexes everything you send it.
Current thread:
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks?, (continued)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Ray Soucy (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Jimmy Hess (Nov 30)
- RE: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Jamie Bowden (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Jeff Wheeler (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Ray Soucy (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Owen DeLong (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Jeff Wheeler (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Ray Soucy (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Mark Blackman (Nov 30)
- RE: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Nathan Eisenberg (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Bill Stewart (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Mark Blackman (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Ray Soucy (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Valdis . Kletnieks (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Leo Bicknell (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Jimmy Hess (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Jimmy Hess (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Leo Bicknell (Nov 30)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Owen DeLong (Nov 29)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Dmitry Cherkasov (Nov 29)
- Re: IPv6 prefixes longer then /64: are they possible in DOCSIS networks? Brzozowski, John (Nov 30)