iptables -t nat -A PREROUTING -i $IF_ETH0 -d $ADR_ETH0 -p tcp --dport 6300 -j DNAT --to $ADR_JNOS:23 Where $IF_ETH0 is your public network device, $ADR_ETH0 is your public internet address, $ADR_JNOS is the IP address of your JNOS. 73! Laci