#!/bin/sh
nic #
 # NAT North's IP to ours
nic #
 iptables -t nat -F POSTROUTING
nic #
 iptables -t nat -A POSTROUTING --source 192.1.3.0/24 --destination 0.0.0.0/0 -p udp -j SNAT --to-source 192.1.2.254:11000-12000
nic #
 # Display the table, so we know it is correct.
nic #
 iptables -t nat -L
Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination         
Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         
Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination         
SNAT       udp  --  192.1.3.0/24         anywhere             to:192.1.2.254:11000-12000
nic #
 echo done.
done.