Not being too familiar with `iptables` myself, I'd love to see the magic invocation they used. Anyone have any idea what that would have looked like?
# Redirect port 8080 to local port 22
iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 8080 -j REDIRECT --to-port 22
iptables -t nat -I PREROUTING -p tcp --dport NNNN -j REDIRECT --to-ports 22