[156392] in North American Network Operators' Group
Re: IPv6 Ignorance
daemon@ATHENA.MIT.EDU (Mark Blackman)
Mon Sep 17 11:16:53 2012
From: Mark Blackman <mark@exonetric.com>
In-Reply-To: <76417C56-97C0-4DAE-9DF5-E8DEA7F0F2C9@logic.org.uk>
Date: Mon, 17 Sep 2012 16:16:14 +0100
To: Adrian Bool <aid@logic.org.uk>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 17 Sep 2012, at 15:55, Adrian Bool <aid@logic.org.uk> wrote:
>=20
> Hi,
>=20
> On 17 Sep 2012, at 15:02, Nick Hilliard <nick@foobar.org> wrote:
>> On 17/09/2012 14:37, Adrian Bool wrote:
>>> It seems a tad unfair that the bottom 80 bits are squandered away =
with a
>>> utilisation rate of something closely approximating zero
>>=20
>> You are thinking in ipv4 mode. In ipv6 mode, the consideration is not =
how
>=20
>> many hosts you have, but how many subnets you are dealing with. =
Instead of
>> thinking of 128 bits of addressing space, we talk about 64 bits of =
subnet
>> space. So your statement comes down to: "it seems a tad unfair that =
the
>> bottom 16 bits are squandered away". This is a more difficult =
argument to
>> make.
>=20
> I don't really agree with the "IPv6 think" concept - but let's put =
that aside for now...
>=20
> The default allocation size from an RIR* to an LIR is a /32. For an =
LIR providing /48 site allocations to their customers, they therefore =
have 16-bits of address space available to them to address their =
customers.
>=20
> So, even in "IPv6 think", homes that typically have one subnet have an =
equal number of bits to address their single subnet as an LIR has to =
address all of their customers.
>=20
> It seems illogical to me that we've got an 128-bit address space, =
featuring numbers far larger than any human can comprehend, yet the =
default allocation to an LIR allows them to address such a feeble number =
as 65,536 customers - a number far smaller than the number of customers =
for medium to large ISPs.
>=20
> The default LIR allocation should be a several orders of magnitude =
greater than the typical customer base - not a smaller default =
allocation.
Amen, brother! I was doing that particular computation about six months =
ago when we had
our first request and arrived at the same conclusion. I've concluded =
that /48 for businesses
and /56 for residential sites is the more reasonable approach until we =
start getting /24 IPv6
allocations for LIRs and I think many others have concluded the same.
- Mark
