[135474] in North American Network Operators' Group
Re: Using IPv6 with prefixes shorter than a /64 on a LAN
daemon@ATHENA.MIT.EDU (Owen DeLong)
Tue Jan 25 19:59:42 2011
From: Owen DeLong <owen@delong.com>
In-Reply-To: <06ad01cbbcee$d91cc210$8b564630$@net>
Date: Tue, 25 Jan 2011 16:57:46 -0800
To: "Tony Hain" <alh-ietf@tndh.net>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Jan 25, 2011, at 4:20 PM, Tony Hain wrote:
> Owen DeLong wrote:
>> ......
>> I suspect that there are probably somewhere between 30,000
>> and 120,000 ISPs world wide that are likely to end up with a /32
>> or shorter prefix.
>=20
> A /32 is the value that a start-up ISP would have. Assuming that there =
is a
> constant average rate of startups/failures per year, the number of =
/32's in
> the system should remain fairly constant over time.=20
>=20
> Every organization with a *real* customer base should have =
significantly
> shorter than a /32. In particular every organization that says "I =
can't give
> my customers prefix length X because I only have a /32" needs to go =
back to
> ARIN today and trade that in for a *real block*. There should be at =
least 10
> organizations in the ARIN region that qualify for a /20 or shorter, =
and most
> would likely be /24 or shorter.=20
>=20
> As Owen said earlier, proposal 121 is intended to help people through =
the
> math. Please read the proposal, and even if you don't want to comment =
on the
> PPML list about it, take that useless /32 back to ARIN and get a *real
> block* today.
>=20
> Tony
>=20
>=20
>=20
>=20
Unfortunately, it's hard for them to do that *today*.
That's the other thing proposal 121 is intended to do is help ARIN make
better allocations for ISPs.
Indeed, a key part of my quoted paragraph above was the "or shorter"
phrase.
Even in that scenario, though, I expect a typical ISP will use a /28,
a moderately large ISP will use a /24, a very large access provider
might use a /20, and only a handful of extremely large providers
are likely to get /16s even under the generous criteria of proposal 121.
Fully deployed, the current internet would probably consume less than
a /12 per RIR if every RIR adopted proposal 121. The 50 year
projections of internet growth would likely have each RIR invading
but not using more than half of their second /12.
Even if every RIR gets to 3 /12s in 50 years, that's still only =
15/512ths
of the initial /3 delegated to unicast space by IETF. There are 6+ more
/3s remaining in the IETF pool.
Owen
