[c-nsp] Full net table too large for Sup720 already?

[jim bartus]

I don't claim to be an expert but I looked into this before and here's
what I found:
http://www.nanog.org/mtg-0702/presentations/fib-desilva.pdf

check out page 8, page 10, and the first bullet point on page 15.

Page 10 says the limit on a 3B is 192k by default but can be tweaked up to 239K.

According to the "Weekly Routing Table Report" cisco posts to nanog
the number currently out there in a full internet bgp feed is 234760.
http://thyme.apnic.net/ap-data/2007/10/20/0400/weekly

So if I understand that correctly a default 720-3B will already
overflow and one that is configured to support the max 239K has less
than 5K left of headroom.

poking through those bgp reports here's the trend:
2007-05-01:	219238
2007-06-01:	221952	+2624
2007-07-01:	224395	+2443
2007-08-01:	227097	+2702
2007-09-01:	229742	+2645
2007-10-01:	233290	+3548

I read that as saying 3B owners have less than 2 months left until
they can't fit a full bgp table in tcam.  Thats not counting any
local/igp routes or arp entries.

If I'm reading right, in about a month c-nsp and nanog will be
inundated with "ow my cpu" posts.

-jim