>>I have full control of a class C address space (yes, I couldn't get just 10
>>addresses), I will do my own primary DNS, and the ISP will provide secondary.
>>I've already invested in DNS/BIND literature, and have a little experience
>>doing this, so it's not a major concern.
>> My NetBSD PC will do routing, and I can assume that the configuration on
>> the ISP end will work properly.  (No ISP horror stories, please :> )
>> I will need to route from sl0 (ISP side) to ed0 (my network).  Any
>> suggestions, config files, ... are welcome.  (help!)

This almost precisely describes my current setup (substitute ppp for sl).

>It's simple and you don't need routed or gated.

I think you do need routed.  You want the outside world to be informed
that your class C network is reachable through your serial port!  Granted,
you could have your ISP hardwire this in their tables, but it's just one
more thing for them to fat-finger at 3AM when their router crashes and they
have to retype the configuration.  Better to just run routed (no arguments)
and have it all happen correctly all by itself.