Serial SLIP Connection

[Dan Plassche <boomer3200%gmail.com@localhost>]

I'm having trouble setting up a direct serial connection on
NetBSD 7.0.2 to share a server's internet access with a client
over SLIP.  The server has internet access over a wired ethernet
card (wm0) and connects to the client over a serial line (null
modem cable).

I started by testing this in virtual machines and I would like to
get it working before deploying to real hardware.  I've been
manually setting up the interfaces, but creating a sliplogin
account with the same settings shown below after running getty on
the server's tty00 did not seem to help as alternatives.

Here's what I've tried so far:

1. Created 2 connected PTY devices to attach one to the serial
port on each QEMU machine:

socat -d -d -4 \
pty,raw,user=dp,group=staff,crnl,echo=0,mode=777,\
link=/usr/home/dp/serial-host \
pty,raw,user=dp,group=staff,crnl,echo=0,mode=777,\
link=/usr/home/dp/serial-client

2. Started QEMU x86 NetBSD server and client attached to each
respective PTY:

qemu-system-i386 -nodefaults -hda nbsd72-server.img \
-chardev tty,path=/usr/home/dp/serial-host,id=ser-tty \
-device isa=serial,chardev=ser-tty -net nic -net user \
-vga std &

qemu-system-i386 -nodefaults -hda nbsd72-client.img \
-chardev tty,path=/usr/home/dp/serial-host,id=ser-tty \
-device isa=serial,chardev=ser-tty -net nic -net user \
-vga std &

3. Dial-out to connect to server from client using -t flag
for local line without modem:

cu -t -s 9600 -l /dev/dty00

4. Escape back to shell (~!) on client and setup sl0 interface:

ifconfig sl0 create
slattach -l -s 9600 -t slip /dev/dty00
ifconfig sl0 inet 10.0.2.7 10.0.2.6 arp up
route add default 10.0.2.6

5. Setup interface on server

ifconfig sl0 create
slattach -l -s 9600 -t slip /dev/tty00
ifconfig sl0 inet 10.0.2.6 10.0.2.7 arp up

Any suggestions would be appreciated!


Thanks,

Dan Plassche