[140526] in North American Network Operators' Group
Re: IPv6 foot-dragging
daemon@ATHENA.MIT.EDU (Jimmy Hess)
Thu May 12 20:39:38 2011
In-Reply-To: <5A6D953473350C4B9995546AFE9939EE0C9E3242@RWC-EX1.corp.seven.com>
Date: Thu, 12 May 2011 19:39:35 -0500
From: Jimmy Hess <mysidia@gmail.com>
To: George Bonser <gbonser@seven.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Thu, May 12, 2011 at 5:49 PM, George Bonser <gbonser@seven.com> wrote:
> Possibly the hit might be the same, but possibly not. =A0An organization
> that requires a second /48 from their upstream might get one that can't
> be aggregated with the previous one. =A0It is my understanding that ARIN
A very important distinction. The _immediate_ hit to the DFZ might be
the same as obtaining PI V6 space,
but the _long term_ hit to the DFZ might be much greater;
particularly if the user starts obtaining
multiple non-aggregable /48s from different sources, or obtains an
additional PI allocation later, but
keeps using the original /48.
It is a heck of a lot better for network stability that any
multi-homed user get a /32 PI,
and find that they will never need more than a /48 of it, than it is
to try to "conserve"
address bits, and require the multi-homed user stick it out with a /48.
With IPv6, bits for addressing networks are not scarce (like they
were with IPv4),
but more importantly, router FIB bits _are_ scarcer.
With IPv4, we face the certainty of address bit assignment exhaustion.
With IPv6, we face a greater risk of address bit _router_ assignment
exhaustion.
Because every IPv6 address has 4x as many bits as an IPv4 address.
And a /48 prefix has consumes at least 2x as many bits as a /24 prefi=
x.
--
-JH
