I just checked the latest sup for my 386 box, and

> #options        TCP_COMPAT_42   # compatibility with 4.2BSD TCP/IP

This one's now toast. We should probably remove it from the mac68k GENERIC
file.

> #options        IPFILTER        # 

This one's actually a pseudo-device (ipfilter). It's needed to let you do
firewal and NAT stuff. I'd recomend it if you're using the mac to bridge
a home net over a dial-up connection. If you get NAT set up right,
all your other local machines have good connectivity w/ only one
dial-up line.

Take care,

Bill