Model : Archer C5

Hardware Version :

Firmware Version : Ver 3.17.1 Build 20160201 Rel 61368

ISP :

I had a problem not being able to forward inbound traffic to desired devices using 'Virtual Servers' settings. I found the only way for inbound traffic to reach a device was to put a SINGLE device in the DMZ. Needing traffic to be forwarded to multiple devices this was not an acceptable solution.

I also discovered the access rules that I created were not being enforced, and were being bypassed completely.
I finally found a simple solution to both problems; however, discovering that solution was anything, but simple.

DISABLE the NAT BOOST feature on the ADVANCED settings tab, then reboot the device.

On the Nat Boost settings page the following note is listed:

Note: 1. If the NAT Boost is enabled, the router will have the best throughput; 2. If the NAT Boost is disabled, the Bandwidth Control can take effect, and it also allows the statistics data been collected; 3. We do recommend to enable NAT Boost for the best performance in normal operation.

The last two words of this note, normal operation, are the keys to this behavior. Judging from observed behavior Port Forwarding, and Access Rules, are not part of normal operation.

With Nat Boost ENABLED, the Access Rules will be ignored, and Port Forwarding will not function, with the exception of a single device in the DMZ.

DISABLE the Nat Boost feature, reboot the device, then Access Rules and Port Forwarding will function as expected and described in the documentation.