routing table size

Tue Jul 30 02:43:51 UTC 2002

> Until then, my money is
> on clueless
> redist connected/statics, large cable/dsl providers who
> announce a /24 per
> pop/city/whatever to their single transit provider, and
> general ignorance.
>
> Why attribute to functionality what can easily be explained by
> incomptence. :)
>
> --
> Richard A Steenbergen <ras at e-gerbil.net>

You forgot one of my favorite frustrations - slow start.

Try this:

a) start an ISP and tell your upstream you want a /21.  They will tell
you that you can only have a /24.

b) Tell them that you understand they can't give you a /21 based on ARIN
guidelines but you would like them to reserve it for you.  Listen to
them laugh.

c) Keep requesting more space as you need it while you grow.  Tell them
you want contiguous space.  Listen to them laugh.  Your choice is take a
new discontinuous block or renumber the whole network.

This would be why we announce  2 /22's and 2 /23's even though given
contiguous space we could make a single announcement.

Add in the $2500 cost of obtaining a ARIN allocation versus what are
'free' addresses from our upstreams and we will probably continue as-is
for a while.  Why does ARIN need $2500 for an entry in a database
anyway?

End result is we would like to make a single announcement.  By being
truthful in requesting address space based on the guidelines we end up
with address space that is fragmented - so we make the extra
announcements.

I have not seen a statistic for non-transit AS's announcing multiple
discontinuous prefixes - I suspect that there are a lot of them for the
same reason we do it.

Obviously you can't keep leaving big 'reserved' holes in your
allocations to downstreams for potential growth.  You can't expect a
network to renumber everytime they need more space.

I don't have a good answer to this problem nor do I expect one - it's
just another reason why we have additional growth in the routing tables.

Mark Radabaugh
Amplex
(419) 833-3635