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RT-AC87U switching 5GHz channels regardless of Control Channel being set.

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mendoza

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My RT-AC87U keeps auto-changing 5GHz channels despite control channel being set firmly to 52. Sometimes it stays on for long hours but just in the last two hours it moved to 48 and 40, then got back to 52. I'm not even using DFS channels, it would have been understandable to get knocked off those.

The thing is, channel 52 isn't even busy. There's one very weak 20MHz network on it. Mine is 80MHz wide. Channels 36-48 are very busy.

I switched firmware to the last available Merlin just because of that but it keeps changing channels just the same.

Firmware: 384.13_202106

Channel bandwidth: 80MHz
Control Channel: 52
Extension Channel: Auto (no other option available at 80MHz bandwidth)

I switched off some options like Multi-User MIMO, 802.11ac Beamforming, Universal Beamforming.

It wouldn't be a problem but unlike some other routers I had, the change isn't instantaneous, takes about a minute of downtime.
 
I just learned 52-64 was also DFS range, thought it was only 100 and above. Makes sense now and understandable why it takes a minute to clear.

Please disregard my original post, apologies for the confusion.
 
I just learned 52-64 was also DFS range, thought it was only 100 and above. Makes sense now and understandable why it takes a minute to clear.

Please disregard my original post, apologies for the confusion.

Not sure where you're located, this is for the US and is helpful to visualize. Similar for most other countries too.

You can leave AC beamforming on, it either helps a bit or doesn't hurt. Universal should be disabled, along with airtime fairness. MIMO is similar to beamforming, for some it might help, others it does nothing, in some cases it can be problematic but not as much as some of the other settings.

I'd just leave the channel selection at auto and see what it picks up.


80211ac_channels.png
 
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can OP or others explain whats the solution? I have AX88 and its infuriating that router changes 80 Mhz channel always to 36-48 WHICH IS OCCUPIED and causes huge problems. when router stays at 52-64, everything works just fine and there is no interfenerce/problems, so why the hell it changes to 36-48? it changes to that band even in auto selection.

are DFS channels banned or something? if yes, then whats the point of 5GHz wifi, if there is just a few viable bands. Living in nordic country.

and I cant even use UNII-3 on AX88....this whole 5Ghz thing drives me nuts....
 
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can OP or others explain whats the solution? I have AX88 and its infuriating that router changes 80 Mhz channel always to 36-48 WHICH IS OCCUPIED and causes huge problems. when router stays at 52-64, everything works just fine and there is no interfenerce/problems, so why the hell it changes to 36-48? it changes to that band even in auto selection.

are DFS channels banned or something? if yes, then whats the point of 5GHz wifi, if there is just a few viable bands. Living in nordic country.

and I cant even use UNII-3 on AX88....this whole 5Ghz thing drives me nuts....

When the router detects a radar signal on DFS, even if weak, it is required to switch channels. This is a legal requirement. Try the upper (149-161) 80 mhz channel as that does not overlap with DFS.

Oh I see you can't use the UNII 3 band. In that case, that's probably why your lower 80mhz channel is the one it picks, that is its only option. You can try some other DFS ranges and see if those stick.
 
You can leave AC beamforming on, it either helps a bit or doesn't hurt. Universal should be disabled, along with airtime fairness. MIMO is similar to beamforming, for some it might help, others it does nothing, in some cases it can be problematic but not as much as some of the other settings.

I'd just leave the channel selection at auto and see what it picks up.

Thanks. I'm leaving it within UNII-1 range for now, to see if it is stable there. It is congested but not impairing performance really.

The thing with DFS is, I live within 5 kilometers (3.5 miles) from an airport which has both civilian and military use. The radars will always keep knocking 5GHz routers off of DFS range.
 
Thanks. I'm leaving it within UNII-1 range for now, to see if it is stable there. It is congested but not impairing performance really.

The thing with DFS is, I live within 5 kilometers (3.5 miles) from an airport which has both civilian and military use. The radars will always keep knocking 5GHz routers off of DFS range.

Yeah, it may or may not be taking up the entire DFS spectrum though. But if it is working ok ok the low channels then you're fine.
 

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