Re: gigabit router (was Re: Getting a "portable" /19 or /20)

["Richard A. Steenbergen" <ras () e-gerbil net>]

On Tue, 10 Apr 2001 alex () yuriev com wrote:

> > Try ~ 10ns ram which you can buy 256MB of for ~ $60-80
> > (www.pricewatch.com). At any rate, A raw 3 or 4 level mtrie FIB fully
> > populated with the real 100k+ routes on the internet consumes less then
> > 900kb, and all the interesting parts fit in the L2 cache of a Celeron A
> > where you can do about 22,000 lookups per MHz. Hardly excessive memory
> > bandwidth. The packet ram on the gige cards is also very fast, and could
> > easily accomidate a dCEF approach.
>
> CEF should be called Customer Enrangement Feature. It is a very very
> very bad idea to have linecards be anything else than forwarders. They
> should not make any intelligent routing decisions. There should not be
> a tons of copies of routing table on line cards.  That is what creates
> problems.

They don't make intelligent routing decisions, the route processor does
then pushes the FORWARDING table down to the individual cards.  There is
nothing wrong with distributed copies of the forwarding table in easy
access of the hardware doing the forwarding, but you should make those
copies over a bus which actually copies things correctly
*coughmbussuckscough*.

-- 
Richard A Steenbergen <ras () e-gerbil net>       http://www.e-gerbil.net/ras
PGP Key ID: 0x138EA177  (67 29 D7 BC E8 18 3E DA  B2 46 B3 D8 14 36 FE B6)