> I have 2 computers (Lc 575 running MacOS, Quadra 700 running NetBSD 1.4.3).
> When I try to ping each other out, I get : ping: "sendto: Machine Arrte"
> What does it mean?

That looks like a localized error message.  It looks like the message
for EHOSTDOWN.  Check the cable and/or hub.  Perhaps a wire got pinched
or something.

> It was working before, so I don't think it's a configuration problem.

Nope.  Sounds like a hardware or driver problem of some sort.

-allen