mailing list archives
Re: The Gorgon's Knot. Was: Re: Verio Peering Question
From: "Patrick W. Gilmore" <patrick () ianai net>
Date: Fri, 28 Sep 2001 14:40:59 -0400
At 06:17 PM 9/28/2001 +0000, Joseph T. Klein wrote:
>Find a way to provide reliable multi homing without massive route
>table growth and you fix many things.
We have, and every backbone is implementing it today, including
Verio. Namely, give people who need to muti-home a /24, and let them
announce that /24 from their own ASN.
Simple, elegant, scalable (although not infinitely, but what is?), and
working today. However, if all backbones took Verio's advice and filtered,
this solution would no longer be workable.
So, you may not fault them for taking a stance, but I do fault them for
taking a stance and then acting in direct contradiction to that stance.
>A more NANOG centric discussion may be to understand how many providers
>would have problems given larger route tables. We all don't have routers
>that can easily chew through a 100,000+ line BGP table.
Then you are in trouble, since the current table is already slightly over
And most core routers at big networks (cisco GSRs, Juniper M###'s), can
handle many more. (Lots of core routers already do - internal tables are
frequently much larger than the global table.)
>How much can we give to individual entities without endangering the
That is not really the question being discussed. Right now we are deciding
*which* entities we can give the freedom to announce what they please.
Verio's "stance" does not prohibit networks or providers with large
allocations to announce whatever they want. Also, many companies, schools,
providers, etc., have very large IP allotments for which they would not
qualify today (e.g. Apple, IBM, GE, MIT, etc. all have /8s.) The filtering
policy does not affect these companies' & providers' announcements in the
Only the new companies, the ones starting small and following the "rules"
by not wasting space or asking for more than they really need, are hurt by
In fact, one of the possible affects of this policy is the depletion of IP
space at a much faster rate. For instance, companies with /24s on their
NAT boxes and 1000s of employees would suddenly want - and qualify for -
larger allocations to allow them to multi-home. Even if they only got a
/20 for the NAT box, that would still increase IP address depletion rates
Not to mention all the other companies & providers who would claim they
need a /20 from the start, when they only need a /24 or less.
Personally, I am far more afraid of running out of IP space than I am of
router vendors not being able to handle 250K routes in a few
years. (Juniper and cisco both claim they can do it today. I know Zebra
can do it today on a single processor fast Pentium III box with a gig of
RAM. Not exactly bleeding edge technology.)
So, how much good does filtering do? And how much damage?
>Joseph T. Klein +1 414 915 7489
Re: Verio Peering Question Craig Pierantozzi (Sep 28)
Re: Verio Peering Question Dorian Kim (Sep 28)
Re: Verio Peering Question up (Sep 28)