I've tried port forwarding to a Linux box on the LAN without success. I noticed this issue with the original releases of CC and had hoped that the issues would have been resolved by now. I sure hope I've somehow missed a configuration otherwise this would be a long standing issue.
This should be a simple process for me since I use Cisco ISO ACL and Linux iptables all the time.
If someone can provide a working example configuration for LEDE Reboot (SNAPSHOT, r3742-894ee95) that would be wonderful.
Basic config of:
Port forward WAN port 10001 to a LAN IP Address port 22
iptables -A INPUT -i eth0 -p tcp -m tcp --dport 10001 -j ACCEPT
iptables -t nat -A PREROUTING -i eth0 -p tcp -m tcp --dport 10001 -j DNAT --to-destination 192.168.200.108:22