Port Forwarding through newer dd-wrt router firmware

I have a new Netgear WNDR3700v2 Dual Channel Router & dd-wrt build 17201 is still broke, GOTCHA!

Lifted almost verbatim from Sean Furukawa's Workaround: Fix dd-wrt Port Forwarding on Netgear WNDR3700 build 16785 article on his blog at www.seanfurukawa.com.

As he phrases it: "So it would appear that there is a bug in the dd-wrt build 16785 (and probably several versions older) on the Netgear WNDR3700. Basically you can set as many Port Forwarding rules you want and they will not work." I have also verifed the problem exists with the WNDR3700v2 running the current build 17201 as well!

He points out that the problem appears to stem from a loopback issue identified for dd-wrt r15760 and later. Both he and I have verified that once the following "Original Fix" actions are taken, port forwarding works! The loopback issue is mentioned in the dd-wrt Port Forwarding Troubleshooting Guide, but the guide does not make clear the extent of it’s impact.

The Original Fix:

Better Fix (if you use QoS stuff):