> Nothing's going wrong with using a Unix box as a router....
> 
> Only that it could slow down the network performance...
> especially if you're using a high speed media.
> Well I don't really know about T1 network... but I think doing a
> routing through any kind of non-dedicated routing OS
> would suffer from processing overhead in the OS kernel.

idunnoman.  gw.home.vix.com is a measily ppro-200 but it runs 20+ shell
sessions, a full news feed, about a message per second of mail traffic
(including some big mailing lists), two ethernets, and a riscom/N2 @T1.
it never seems fast, even in single user mode.  but it never seems slow
either.  i think the above text is repeating an urban legend.  my mileage
varies.  use a router if it makes you more comfortable or if you can't
make your unix host do what you want or if you have a spare router.  but
if you want to use a single host to do everything, including route, then
don't let performance concerns tempt you otherwise.