[nullius]

Hi,

Running Firmware: DD-WRT v3.0-r47086 std (07/22/21) (But happened on older firmwares as well).
After an AP died on me (running also DD-WRT on same hardware as router but as an AP only) I did an emergency replace to a TP-Link Archer C6 (keeping the stock firmware temporarily). At that point devices in my home started identifying a 5GHz signal that was not there before.
It appears that the 5GHz was never actually working and I was always connected at 2.4 throughout the house. This holds true for both APs (the one at the router and the one acting as range extension).
Running a wifi analyzer on my phone I am able to see under the 5GHz bands an ssid whom I can clearly identify belonging to my router (shut ath1 down and it goes away). But as stated it is HIDDEN and not broadcasting the ssid for some reason although it is set to do so.

Attached an image with my current (basic only) settings. I have not changed anything in advanced

Any ideas what to try? Any additional info needed to debug this?

Thanks!

[kernel-panic69]

I presume the router in question is a TP-Link Archer C7, but no idea which version (v1, v2, v3, v4, or v5). It would help to know which device it is, specifically. Reason being is that the 5GHz radio is not supported on the v1.

https://wiki.dd-wrt.com/wiki/index.php/TP_Link_Archer_C7

[nullius]

It is an Archer C7 and a V5 (sorry was sure I mentioned that in the original post).
In the meantime, I continued debugging this and found the following:
While that hidden network I mentioned is in fact somehow connected to the router it is not the only 5GHz channel active. There was another channel active at the end of the spectrum so I didn't see it clearly in the analyzer. I have now set the channel manually, shut down the secondary access point and can confirm that I do have a broadcast ssid under 5GHz.
Still however, it appears my devices are connecting to the 2.4. When connecting to a 5GHz connection my phone shows a 600 Mb/s wifi connection. Right now I can't get it above 170 unless connected to that aforementioned Archer C6 with stock firmware. Same with TVs when choosing a wifi network on the TV 5GHz connections are marked as such and the DD-WRT based routers aren't showing up like that.

What else should I check?

[kernel-panic69]

Refer to the QCA wireless settings wiki or sticky. There is some debate on the settings, but you should be able to find something that does work. Connection speed and throughput rely on the client hardware, mostly. Also depends on the configuration in the router for channel width and what the client hardware supports. You are not going to see fat rips of bandwidth on most mobile devices and wired ethernet is still King.

[ho1Aetoo]

Is the correct regulatory domain set?

1. set the correct regulatory domain
2. set a channel that is supported by the end devices
3. set different SSID's for 2,4 and 5Ghz (only as a test, then you can distinguish the networks visually better)

[nullius]

Hi again,

So I've continued trying to understand what's going on and here are my latest findings:

I was able to achieve a situation where devices capable of identifying a 5GHz channel (e.g my televisions) were in fact do so and displaying it.
My phone (Samsung Galaxy S21 Ultra) on the other hand was behaving in way that I cannot explain. When connected to a 5GHz channel on the stock tp-link firmware, when entering the connected SSID network details (in the phone itself) it was showing 800+ Mbps speeds.
When connecting to an "isolated" 5GHz SSID on the DD WRT firmware (I changed names as suggested to make sure what I'm connecting to), I was showing speeds of ~170 Mbps at most.
Maybe this is expected behavior but it didn't add up...

Any ideas? Maybe I am missing something fundamental on how this is supposed to work?

[ho1Aetoo]

173Mbit (please always state the correct rates) should correspond to 20Mhz channel width with 2 antennas

This also corresponds to the channel width you set above in the first post.
For 866Mbit you have to set 80Mhz channel width



I don't see an error here, at most what you have configured

[nullius]

This is probably the "fundamental thing" I was missing.

Thank you! 🙏