[99922] in North American Network Operators' Group
Re: Upstreams blocking /24s? (was Re: How Not to Multihome)
daemon@ATHENA.MIT.EDU (Patrick W. Gilmore)
Mon Oct 8 23:17:13 2007
In-Reply-To: <4BB6684D-80E1-450F-84AE-8C26DB14C3EC@virtualized.org>
Cc: "Patrick W. Gilmore" <patrick@ianai.net>
From: "Patrick W. Gilmore" <patrick@ianai.net>
Date: Mon, 8 Oct 2007 23:14:44 -0400
To: nanog@merit.edu
Errors-To: owner-nanog@merit.edu
On Oct 8, 2007, at 10:28 PM, David Conrad wrote:
> The argument, as I understand it (and those who argue this
> direction feel free to correct me if I misstate), is that as the
> IPv4 free pool exhausts, there will be a natural pressure to
> increase address utilization efficiency. This will likely mean
> longer prefixes will begin to be put (back) into use, either from
> assignments and allocations that were "rediscovered" or from unused
> portions of shorter prefixes. Customers will approach ISPs to get
> these long prefixes routed, shopping through ISPs until they find
> one that will accept their money and propagate the long prefix.
>
> Now, of course announcing a route doesn't mean anyone will accept
> it, but as I understand the theory, larger ISPs will agree to
> accept and propagate longer prefixes from other larger ISPs if
> those other ISPs will be willing to accept and propagate
> transmitted long prefixes ("scratch my back and I'll scratch
> yours"), particularly if this encourages the smaller ISPs to 'look
> for other employment opportunities' when they can't afford the
> router upgrades.
We know this is not the case from history. For instance, look at
Sprint & ACL112.
Also, we know from history that smaller ISPs sometimes are better
able to do router upgrades than large ones.
> Personally, I fully expect the first part to happen. Where I'm
> having trouble is the second part (the accepting longer prefixes
> part). However, a few prominent members of the Internet operations
> community whom I respect have argued strongly that this is going to
> happen. I thought I'd ask around to see what other folk think...
I'd bet against the first part happening, so the second part is moot.
--
TTFN,
patrick
