Question ASUS AX82U with mesh node: WiFi suddenly spotty, hardline working fine

[phidelt649]

Hi all! I’m currently running an AX82U with an RT-AX1800S as a node. It’s been rock solid for over a year but over the past two weeks, my wifi (on both channels) has been trash. It seems to randomly go in and out to where I need to shut off my phones WiFi to do anything. However, our hardwired equipment is working just fine and still holding up speeds consistently (600-800mb).

I tried power cycling both the modem and the router which seems to fix the issue briefly but it always returns. I then upgraded both modules firmware to the latest and that seemed to fix it for a couple of days but now we are back to trash again. The modem is mine and is a surfboard DOCSIS3.1 I think.

Any suggestions on what to do from here? Roll back firmware? Is the main router on the fritz (originally purchased in July 2021)? I also have the main router plugged into a UPS but I don’t think that would be an issue?

I’m not great with this networking stuff and I think I’m officially at the depth of my knowledge. Thanks again!

 

[dwd999]

With wifi the first question is always how close are your neighbors? You could use a wifi analyzer app like the free one by Matt Hafner in the Microsoft store to see how many competing wifi signals there may be from your neighbors and how many signals there are on the same channel as you. It also helps to know how your routers are set, are they set to transmit on a fixed channel or are they set to auto where competing signals can result in your router changing to another channel which may not be as strong and which may result in lower throughput.

 

[phidelt649]

Thank you for the response! We live in a closely packed suburb with neighbors on both sides. It seems to have miraculously fixed itself after I yet again hard reset it but we will see. I attempted to check the channel thing you mentioned but couldn’t find the setting in the ASUS router app despite Googling it. Oddly enough, the 2.4gHz band works fine, albeit painfully slow. Any idea where I could find that setting you mentioned?

 

[dwd999]

Its labelled Control Channel in the 3.15.1 Wireless section of the settings. There's a page of settings for each band. Refer to pages 83 and 84 Item 7 in your manual.

https://dlcdnets.asus.com/pub/ASUS/...X82U_RT-AX82U_V2_UM_v2_WEB.pdf?model=RT-AX82U

I usually manually set the channel to the lowest one in each band since the lower channels are usually the strongest. Hopefully if your neighbors have their routers set to the default Auto setting then they'll move onto a higher channel and leave you alone on your channel.

 

[phidelt649]

Thank you for the response! I was on channel 40 and the lowest channel available was 36 so I set it to that. I’ll report back if it stabilizes!

 

[bill001g]

It would be nice if router makers were more clear about what happens when you choose a particular channel number.

The problem is those channel number actually only represent 20mhz of bandwidth. In most cases you are using at least 40mhz on 5ghz and a lot of times 80 or even attempting 160.

In some routers it will choose the nearest group of channels that the block you selected is within the range and also the channels on either side to get the higher bandwidth. Other router the number you select also dictates the maximum channel width that is supported. Note this is made even more confusing because the router will run different channel width to different clients connecting to the same radio.

So this is the wiki page I like to use that shows the channel numbers and how they related to the channel width. The 5ghz part is about 1/2 down.

https://en.wikipedia.org/wiki/List_of_WLAN_channels

The key thing here is in addition to avoiding your neighbors you also have issue using the bands marked DFS. These are radio bands actually used by other services, weather radar is a common example. Many routers you can not choose the channels that overlap these manually. The router must detect competing signals and stop using them if it detects other traffic. Also many end devices do not support using these restricted channels so even if the router does your end device might not be able to connect.

What might be happening when you change the channel number you are using you might also be reducing the channel width. I am not sure if your router supports it or not but I would not let it attempt to use 160mhz radio bands. These all overlap the DFS areas and it also means you overlap every neighbor using a 5ghz router. If you want to use 160mhz you should buy wifi6e and run on the 6ghz radio band.

 

[phidelt649]

I’m at a complete loss here guys. I messed with it all night and nothing. This has been going on for about two weeks after being rock solid steady for 3 years. I changed the channel. I even dropped down to the 2.4gHz channel and that didn’t work either.

Do I need to just a brand new router? Could this be a hardware issue? I don’t care at this point what it costs, I see patients via telehealth so I -have- to figure this out.

I do have the unit plugged into a Cyberpower UPS, would that matter in any way? I’m not sure what else to do at this point. All of my hardwired stuff is working fine, it’s just the wifi. Any help or suggestions would be greatly appreciated!!

 

[bill001g]

So is the second router running as a repeater or do you have it cabled to the main router and are running it as a AP.

If we assume it is a AP and you use different SSID so you know exactly which unit you connect to then I would suspect the end device and not your router.

It would be unlikely for a router to have issue with both 2.4 and 5g. A router has 2 different radio chips. Your end device though only has 1 radio chip and change the frequency so if it has a issue it will have a issue on both radio bands many times.

 

[phidelt649]

Full disclosure, I rarely know what I’m doing when it comes to networking.

We were having dead spots in the downstairs areas so I hardwired the second router and then used the ASUS app to do a mesh setup. I let the program do it all and it ran flawlessly for like a year until very recently. My 2.4gHz channel works all the time but it tops out at around 10-20mbs while hardwired gets 800-900 and the 5gHz channel, when it’s functioning gets 400-600.

Does that help at all? Sorry like I said, I have no clue when it comes to troubleshooting networking stuff.

 

[bill001g]

Hardwired to the second router is the best.

I am going to assume the asus app assigned the same SSID name to both the main router and the secondary router ??

Although it tend to be simpler for many people the new issue is you have no control over where your wifi devices connect. In theory at least it should connect to the strongest signal. It is not uncommon though for it to connect to the wrong signal. This might explain why all the sudden the it has a issue.

Now if the issue is that there is some defect in the 5ghz radio chip you have the problem of which of the 2 routers is having the issue. It is pretty rare to have a hardware failure.

Maybe try to turn off the remote router just to test. You will then know you are connecting to the main router. If the signal is very weak though it may not connect. That would mean that your pc is connecting to the remote router.