PC Routers (was Re: /24s run amuck)

Thu Jan 15 04:16:22 UTC 2004

> I also think that it is extremely important to seperate "what you can do 
> with a redhat cd and a dream" from "what someone can do with PC hardware".
Absolutely correct ;)

> The bottom line is: You are only going to get so much performance when
> you forward packets through a box which is processing an interrupt per
> packet, doing a patricia tree lookup per packet, copying the packet in
> memory a couple times, and doing some sequential comparisons through a
> firewall ruleset on every packet. None of the above has anything to do
> with PC hardware, but rather the poor software that people currently
> making "PC routers" choose to run.
> 
> If someone were to take *half* the software innovations which have been
> made over the past 15 years (a decent fib, interrupt coalescing,
> compiled packet matching rulesets, etc) and applied them as if they knew
> something about networking and coding, they could very easily produce a
> box using off the shelf PC hardware which woops up on a 7206vxr for
> somewhere less than $2000. If there is one thing PC hardware is good at,
> it is getting faster fast enough to keep up with the amount of bad code
> people keep churning out. :) Of course, then they would probably need to
> know a little bit more about routing protocols than just "how to compile
> zebra", but assuming they did that too... They would be bought by Cisco.
> :)
You may find it interesting that both Linux and FreeBSD now have interrupt 
coalescing, and www.hipac.org is building a compiled ruleset.

As far as broken-ness of linux rib/route lookup code: Yes, it is so very 
1985, but there may be changes coming soon [Pilosoft may be sponsoring a 
rewrite].

> Anything else is either a cute playtoy for your house, or an endless
> source of laughter for the people who know better as they watch you work
> away at it. The vast majority of this discussion falls into the latter
> category, but after a while even this gem of a subject turns from funny
> to just plain sad. :)
...Until they get bought by Cisco? ;)