Route an IP from WAN to a host on LAN on OpenWRT

This is copied from the OpenWRT Page concerning your router:

Wired stations cannot ping each other

This is a known bug: "switch eth0(Atheros AR8316) no traffic between ports possible" Based on the comments from the bug you can try these commands:

swconfig dev eth0 vlan 1 set ports "0 1 2 3 4 5"
swconfig dev eth0 set apply

If these work you can add the following lines to your /etc/config/network:

config switch
  option name 'eth0'
  option reset    '1'


config switch_vlan
  option vlan '1'
  option device   'eth0'
  option ports    '0 1 2 3 4 5'

I have met similar problem and I can share solution which appears to be very simple. In OpenWRT the feature you are looking at is plain port forward.

Open you router IP, typically http://192.168.1.1

In Network menu, choose Firewall, the Port Frowards. Scroll down to "New port forward" and add:

• Name: ALL->DMZ
• Protocol: choose do you need both TCP=UDP or just TCP
• External zone: wan
• External Port: leave empty!!!
• Internal zone: lan
• Internal IP address: choose IP of host, in your case it's NAS
• Internal port: leave empty!!!

Click Add, and Save & Apply.

That will work exactly the same as in other routers firmware "DMZ host", the host with ALL external traffic redirected to it by default.

To have more security I recommend you to forward only ports you need, without exposing it widely to Internet.

If you will want to add additional SINGLE Port Forwards, they will be added to the end of list. IMPORTANT: always move rule ALL->DMZ to the bottom of the list and "Save & Apply". The rules are processed in the order, so the first one met condition and others do not work.

Best Regards, Arunas B.