large clusters and topologies

[Greg Lindahl]

> that and you can now get fast-ether switches with port-counts up to about
> 384 ports which isn't to shabby compared to the denisty of most other
> lan-interconnects.

Actually, you've been able to get those for quite a while. Centurion at UVa
was built in late 1998 with a 288 port switch, which was composed of 12
24-port switches with gigabit uplinks, and a 12-port gigabit switch. It's
dense, but the particular stuff I usd (3com) was expensive in today's terms.

Today you can both buy chassis switches with a gazillion ports (but often
limited backplane bandwiths), or cobble together lots of cheaper switches
such as HP 4000M procurves with copper gigabit uplinks and a gigabit switch.
The same philosophy, but the details as to who makes the most cost-effective
components keeps changing over time.

We tried to keep an up-to-date document describing how to build cheap
ethernet switches for various sizes, but it was too hard to keep it from
bitrotting.

-- greg

p.s. and, incredibly enough, if you want an 80 port HP4000M, it's still
cheaper to buy 2 40-port boxes and throw away the second chassis than it is
to buy expansion cards.