[75716] in North American Network Operators' Group
Re: who gets a /32 [Re: IPV6 renumbering painless?]
daemon@ATHENA.MIT.EDU (Stephen Sprunk)
Sun Nov 21 15:19:27 2004
From: "Stephen Sprunk" <stephen@sprunk.org>
To: "Paul Vixie" <vixie@vix.com>
Cc: "North American Noise and Off-topic Gripes" <nanog@merit.edu>
Date: Sun, 21 Nov 2004 13:57:08 -0600
Errors-To: owner-nanog-outgoing@merit.edu
Somebody said:
>> >if the ipv6 routing table ever gets as large as the ipv4 routing table
>> >is
>> >today (late 2004 if you're going to quote me later), we'll be in deep
>> >doo.
>>
>> *WHEN* the ipv6 routing table gets as large as the ipv4 routing table
>> is today (late 2004, when you quote me later) it won't be a problem.
Agreed. When the IPv6 table has as many routes as today's IPv4 table, we'll
need four times the storage; Moore's Law says, as long as that doesn't
happen within 36 months, it's not a problem. I haven't seen anyone
(recently) predict IPv6 adoption will be anywhere near that fast, much less
faster.
Thus spake "Paul Vixie" <vixie@vix.com>
> but it's not just the routers, it's churn. "it's always noon somewhere."
> the stability of the distributed system called "the global routing table"
> is directly proportional to its size. the number of participants in that
> system, each of whom must build their own model of the system using only
> the messages they get from direct neighbors, cannot usefully exceed *some*
> maximum for any given total number of discrete destinations.
...
> first, the current distance-vector approach used by BGP just
> won't scale to O(1e12),
Probably not, even if router vendors start using reasonably modern
processors.
> and second, i don't think that you think that there are enough
> participants
> who want to own routers to make such a table size necessary.
As a point of reference, today in IPv4 there are 16k origin-only ASes.
Assuming reasonably sane RIR policies, we can expect -- even with the issue
of one PI prefix per AS -- that there would be 16k end-site PI routes today,
with linear growth similar to the current allocation rate of ASNs. This is
not even remotely a problem until well after we have to switch to 32-bit
ASNs; in fact, the situation will be far better than what we will likely
have with IPv4 at that point.
> mr. doran argued for many years that routing table slots should be
> auctioned or leased. i never did and still do not agree with him, but his
> starting assumptions weren't and aren't my point of disagreement.
The idea has obvious appeal, but it seems like a clear case of the cure
being worse than the illness once you consider the logistical and technical
requirements.
S
Stephen Sprunk "God does not play dice." --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSS dice at every possible opportunity." --Stephen Hawking
