Ok NetBSD network gurus here's a cool one:

We've got a little apartment network going here as like so:

------------   ------------------   --------   -------
|Pentium   |   |PowerMac        |   |IIvx  |   |486  |
|Win NT    |---|Linux-pmac/MacOS|---|NetBSD|---|Linux|
------------   ------------------   --------   -------
            ^                                     |
            10-Base-2                             | < Serial Line
                                                Modem

The local network is 192.168.1.x. Anytime we want to address a local
node we use a Hosts file. If we want to access the outside world then
the 486 box kindly does IP Masquerading with diald to connect to the
outside world and give the network access. So the 486 box is essentially
the gateway/router for the apartment.

Anyway, about 2 months ago my roomate booted windows on the 486 and it seemed
that having the IIvx on was causing windows to crash. Turning it off seemed
to cause it not to crash. My roomate surmised this was because the IIvx
wanted to use the gateway for whatever reason and he didn't have the
ethernet drivers installed thus causing Windows to puke (great Microsloth
stuff, huh?). I thought this was a fluke.

Recently I booted into MacOS on my PowerPC and I tried using the network
with open-transport. Sometimes when I opened NCSA telnet I get messages
about not being able to open TCP Name Resolver and network access in general
has been very spotty at best, especially in the name services department.
So I had a hunch and I shut off the IIvx. Reboot, and voila! Everything
works without a hitch.

On a side note I've just re-installed Linux-pmac and I've been having network
setup troubles. I wonder if this is related...

Anyway, I'm wondering if this is a hardware screw up, a kernel problem, or
just a general setup gaff on my part. I didn't touch the NetBSD network
setup too much from the normal install, just added my name, a few name
servers to resolv.conf, the gateway name, and some names to the hosts file.
 
Anybody have an idea?