I use netbsd 1.3.1 on IIci as dial-up server. PPP and IPNAT work fine. (The
kernel is the improved-ipfilter version which was discussed on this ML. 
The natatalk disabled. )
This box has no monitors connetcted directly. So I use PowerMac8500/180 as
a serial terminal (by way of printer port) . Of course I can also use the
telnet through Ethernet.
The PowerMac8500/180 (client) often freezes up with tasks such as
QuarkXpress or Adobe Illustrator, I must restart it. After that, I take a
look into bsd-box on serial terminal, it always falls into debagger like;

no such command
db>

Contrary, other clients connected to the network shutdown or restart,  the
bsd-box does not suffer.
What's wrong? ( I changed /etc/ttys in various way, but it had no effects.
) Anyone who has a similar symptoms?
$B5\>k0BAm(B
azusa@po.iijnet.or.jp