> My question is, should I switch the Mac, which already has a fast 
> NIC, to NetBSD PPC and run Samba there, and use the old 486/33 (which 
> already has a 56K modem and a 10 MBit NIC) for Internet routing?

Unless you have a very big internet pipe the 486 will be able to deal with
that job just fine. I used a similar machine (486/50) as my DSL router (and
later replaced it, for completely unrelated reasons, with an even slower
Sparc Station 2). The SS2 now uses about 10% CPU load. This includes IP Filter
and MSS clamping.

Martin