Reroute traffic for Linux:
 iptables -t nat -A OUTPUT --dst EXTERNAL_IP -p tcp --dport 9000:9010 -j DNAT --to-destination INTERNAL_IP
 iptables -t nat -A OUTPUT --dst EXTERNAL_IP -p udp --dport 9000:9010 -j DNAT --to-destination INTERNAL_IP
 service iptables restart

Those iptables lines will redirect any traffic going to EXTERNAL_IP on ports 9000 to 9010 to INTERNAL_IP. The internal ip is the LAN-IP of your server, and External ip is your internet IP. Use the above iptables command on all internal machines except your gateway/router. This assumes your gateway/router machine does not also host your sim. This also assume you have a default ACCEPT policy on your internal machines. So to connect from within your LAN, use the above iptables commands to reroute the traffic to the server internal ip.