[156404] in North American Network Operators' Group
Re: IPv6 Ignorance
daemon@ATHENA.MIT.EDU (Owen DeLong)
Mon Sep 17 14:33:41 2012
From: Owen DeLong <owen@delong.com>
In-Reply-To: <D87DAC89-F521-4F55-80A7-97EFE30F90E3@exonetric.com>
Date: Mon, 17 Sep 2012 11:28:56 -0700
To: Mark Blackman <mark@exonetric.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Sep 17, 2012, at 08:16 , Mark Blackman <mark@exonetric.com> wrote:
>=20
> On 17 Sep 2012, at 15:55, Adrian Bool <aid@logic.org.uk> wrote:
>=20
>>=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.
>=20
> 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.
>=20
> - Mark
>=20
LIRs which need /24s can get /24s.
/32 was never a maximum, it was merely the minimum and as such is a =
reasonable starting point.
The vast majority of ISPs in operation today can give all their =
customers /48s out of a /28 and still have lots of room to spare.
For larger providers, they should have no trouble justifying a much =
larger block.
I know from experience that it is possible to get /24s in the ARIN =
region with reasonable justification, for example.
Owen
