Enable DFS/TPC 5Ghz WiFi Channels on RT-AC68U B1

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Occasional Visitor
Is it possible to enable DFS/TPC 5Ghz wifi channels on the RT-AC68U B1 router running Merlin firmware or does this router not support these additional channels physically? Almost all of the DFS/TPC channels are allowed in my country but none of them are listed when choosing the 5Ghz wifi channel. If it's possible to enable these is there any information on how to do so?



Part of the Furniture


Part of the Furniture
What router model do you actually have? Your past posts are contradictory. Is it an RT-AC66U, and RT-AC68U or an RT-AC66U_B1? Is the "B1" part of the model name or just the hardware revision?

What firmware version is it running?

What country was it purchased from?
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Asuswrt-Merlin dev
If DFS channels aren't listed, then they aren't supported, and that cannot be changed.

Make WiFi Great Again

Regular Contributor
Very Respectfully, Merlin, I dont believe that is entirely correct and I will explain why in a few sentences down. To the op, if you want DFS on an ac68u, you will need to flash an older Merlin based firmware such as johns fork OR an alternative firmware like dd-wrt or fresh-tomato, both of which have modern (as of march 2021) firmwares with modern(late 2020 or better drivers) that still have enabled the DFS channels. I know this because I have this router (actually 4 of the ac68u) and use all 4 mentioned firmwares as a hobby to play with settings and compare the differences between firmwares, mess with scripts etc so I know this to be true. it's only the asus stock firmware and merlins firmwares that are more recent then johns fork that frustratingly, have the DFS channels locked down and not available.
I dont know why this is because DFS is legally allowed in my country (USA) as well as a host of other nations.

Ive seen others suggest that the more recent Broadcom drivers have DFS disabled and maybe thats why and I have no arguement with that other then to say that Fresh-Tomato and dd-wrt use broadcom drivers less then a few months old and they support DFS....


Asuswrt-Merlin dev
I dont know why this is because DFS is legally allowed in my country (USA) as well as a host of other nations.
Because for a device to offer DFS channels, the manufacturer must have the FCC validate it for DFS channel usage. Asus didn't do so with the RT-AC68U, hence it's not supported by the stock firmware or my firmware, and won't be unless Asus were to resubmit the router for validation.

The fact that older/non conforming firmwares allows it is in violation of FCC regulations, and I have zero plan of going against that, even if could - which I can't. Newer drivers are more tightly locked down.


Part of the Furniture
Out of the box, my fork firmware follows all the country regulations for channel availability. As mentioned, it's not as tightly locked down...but you are on your own if you make changes.

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