[9fans] NAT'ing a drawterm connection

[rgr@sdf.lonestar.org (Rob Ristroph)]

I have a cpu/auth server on a private network, which is connected to
the internet via a Linux computer running iptables and masquerading or
NAT'ing as they call it now.

 From that linux box I can drawterm into my Plan 9 cpu/auth server.

I would like to forward the appropriate ports so that someone on the
internet at large can drawterm to my plan 9 machine.

Here was my first attempt:

# Port forwarding to try to make drawterm to Plan 9 machine work
/sbin/iptables -t nat -A PREROUTING -p tcp --dport 567 -i eth0 -j DNAT --to 192.168.1.18:567
/sbin/iptables -t nat -A PREROUTING -p tcp --dport 567 -i eth0 -j DNAT --to 192.168.1.18:17007
/sbin/iptables -t nat -A PREROUTING -p tcp --dport 567 -i eth0 -j DNAT --to 192.168.1.18:17008

However it doesn't work.

Has anyone set this up before ?

If the connections on 170xx are initiated from the Plan 9 side, I
don't need those last two lines, right ?  For simplicity let's presume
the client drawterm has a real IP address.

--Rob