[124084] in North American Network Operators' Group
Re: IP4 Space
daemon@ATHENA.MIT.EDU (Owen DeLong)
Tue Mar 23 03:44:35 2010
From: Owen DeLong <owen@delong.com>
In-Reply-To: <290C0D04-9161-4AF6-898B-FCD795556539@internode.com.au>
Date: Tue, 23 Mar 2010 00:40:00 -0700
To: Mark Newton <newton@internode.com.au>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Mar 22, 2010, at 10:27 PM, Mark Newton wrote:
>=20
> On 23/03/2010, at 3:43 PM, Owen DeLong wrote:
>>=20
>> With the smaller routing table afforded by IPv6, this will be less =
expensive. As a result, I suspect there will be more IPv6 small =
multihomers.
>> That's generally a good thing.
>=20
> Puzzled: How does the IPv6 routing table get smaller?
>=20
Compared to IPv4? Because we don't do slow start, so, major providers =
won't be
advertising 50-5,000 prefixes for a single autonomous system.
> There's currently social pressure against deaggregation, but given =
time
> why do you think the same drivers that lead to v4 deaggregation won't =
also
> lead to v6 deaggregation?
>=20
I think that the same drivers will apply, but, think of IPv6 as a Big =
10->1
reset button on those drivers. Sure, in 30 years, we may be back to
a 300,000 prefix table, but, in 30 years, a 300,000 prefix table will be
well within the hardware capabilities instead of on the ragged edge
we face today.
> (small multihomers means more discontiguous blocks of PI space too, =
right?)
>=20
Yep. It does. However, IPv6 gives us a 30-50,000 prefix table now =
(when
we get there) and 10-30 years to solve either the TCAM scaling issue or
come up with a better routing paradigm.
I think that eventually an ID/Locator split paradigm will emerge that is=20=
deployable. I think that SHIM6 and the others proposed so far are far
too complex and end-host dependent to ever be deployable.
Likely we will need to modify the packet header to be able to =
incorporate
a locator in the header in the DFZ and do some translation at the edge.
I haven't fully figured out the ideal solution, but, I think several =
others
are working on it, too.
Owen
