Help needed, wifi 2.4 is slowing down, and eventually all clients drop

[Pergola Fabio]

Guys, i need some help here
my devices are rt-ac88u as main router => 386.3_2, and 2 x nodes rt-ac86u running stock 3.0.0.4.386_44470-g53bccb8

All is ok, but after a day, i see my wifi speeds dropping, i only have issues with the 2.4 Mhz
Notebook is connected with 144Mbs , when i copy files over the network, the copy speed is like 11MB/sec, this the speed expected
one day later, i only have like max 1 MB sec, i also notice it on the smartphones, browsing is terrible slow , if i do a speedtest online, i get speeds like max 5 Mbbs, while it should be more like 80 Mbs
If i restart the wireless, all is back to normal, untill a few days later

I see this bevaviour on main router and nodes, so it must be a setting... i already played with the channels like 1,6,11 or auto, no difference...
Also no neighbors here, so no interference...

below some screenshots? what am i missing? how can i troubeshoot this?
all devices are factory resetted after a firmware upgrade

thnx , much appreciated

 

[sbsnb]

If it were me I would start with fundamentals. See if changing the control channel to 1 or 6 has any effect.

 

[Pergola Fabio]

already tested those, no difference

 

[sbsnb]

Since you see the issue from all nodes it's extremely unlikely to be an issue with the router(s). I would start looking for non-WiFi sources of interference. Bluetooth devices, a leaky microwave oven, USB on the router, baby monitor, cordless phone, wireless headphones, etc.

 

[Pergola Fabio]

no, thats normall not possible
in the attick were my last node is, there are no devices there

it seems like somekind of memory issue? its slower and slower over time, and eventually crashes
i was looking at the log files, i see this occuring , not sure if its related?

nvram: consolidating space

no other strange things in log files

 

[Adooni]

hm 2.4 wi-fi is not user often by my friends but I got 2 reports lately that something is wrong, hard to connect. low speed.
if you would like to test it I would save cfg file and load 0.5y old firmware to all routers and retest. Asus is trying to fix AiMesh from alpha release and doing this they do a mess.

 

[Pergola Fabio]

dont think its an aimesh issue, it also happens on main router
i am now testing 40mhz only speed instead if 20 or 20/40

 

[Adooni]

I did not stated it is AiMesh issue - AiMesh issue is from the cave age . When they try to do something with it they mess 2.4Wi-fi
I have one AC68U that had issue with RMerlin/AsusWRT for last few months but I put FreshTomato there few weeks ago and all phones about it end from my friend site.
2nd A68U is on 384.19 RMerlin did not updated, I will have access to it on Christmas it and no issue. RMerlin is not changing wi-fi that is done by AsusWRT.

 

[Pergola Fabio]

hmm, dont think its firmware related, otherwise more people were complaining
ac88u and 86u are popular devices

 

[sbsnb]

A memory issue wouldn't manifest on three devices simultaneously. I'll bet money the cause is external to the routers.

 

[ScottK123]

Hi!
I am having a similar issue as well!
Running the newest firmware 386.3_2 on an older RT-AC68U, which I have set up to be just an "AP mode", not a Router.

My 2.4 Wifi clients will stay connected for a day or 2, then they start to fall off one by one, and eventually all are disconnected, but keep trying to connect.
(I have a number of IOT devices, so they just keep trying if they can't connect)

My Thermostat (Honeywell) is one of these devices.
When it fell offline, I poked around in there, and noticed it said that its failure was "Bad password".

So that had me wandering on the Router/AP, looking at password/authentication areas/logs.

I found exactly what I needed to see in Advanced Settings -> System Log -> Wireless Log.

When the devices are connected properly and happy, they all have the "U" flag set (Authenticated)

When this issue occurs, nearly every Wifi 2.4 device connected has the "U" flag unset!
You can also see the IOT devices connecting, trying to presumably log in with the password, fail, and disconnect.
Rinse and repeat.

This error condition lasts forever until I either reboot the Router (AP Mode), or I do something with the Wifi settings, for example, I went into my Guest Network, and just changed "Enable Mac Filter" from Accept to Disable, and then back.
(I don't think it matters what you change, I think it just matters that the Wifi gets modified in some way, as to cause the merlin firmware to refresh the Wifi)

Once you Apply the settings, you can watch the clients all pile back onto the 2.4, and this time they all have "U" (Authenticated) set properly!

PS: This all started happening when I went up to 386.3_2.

(But I don't remember the firmware version where I came from, so I might have to hunt back a few versions until I find one that doesn't have this issue.

Pergola, when it happens again, can you check your "Wireless Log" and see if you see the same thing I do?

 

[Morris]

I'm guessing this is a 2.4Ghz environment issue. if you are in a urban or suburban environment, other people's 2,4Ghz devices or even your own are the cause. I'd change two things in your config:
1- Change channel to Auto. This will move your channel when other strong signals are detected on the same channel.
2- Enable Blue Tooth Coexistence

Also, have a talk with the person that has a 2.4Ghz only router and is gaming! Also, do not change the channel width to 40 or 20/40 as some mentioned. This will increase the possibility interference and should only be used in rural environments.

Good luck,

Morris

 

[128bit]

don't mean to pile-on here, guys but i may have a me-too going on with my rt86u. since upgrading from "stock" last week, the 2.4 band has been weird. all boxes connect but there are times when the speeds are in the mid 20s when normally i see 150 -180 on that radio with these laptops. no disconnects that i can see but when i reboot the router, everything's lovely again for 48 hours or so,

when i made the leap, i thought i did do 2 full resets but they didn't take. rtm on how to "truly" reset the box and it finally worked; but only did that once. the 5g band seems to be just a tad weaker as well.

haven't done any g2 per se as i'm still lovin' on the merlin feats in this code. will post again once i have something to report. so for now, this is simply an fyi.

 

[Pergola Fabio]

@ScottK123 will have a look next time at the wireless log

 

[Morris]

don't mean to pile-on here, guys but i may have a me-too going on with my rt86u. since upgrading from "stock" last week, the 2.4 band has been weird. all boxes connect but there are times when the speeds are in the mid 20s when normally i see 150 -180 on that radio with these laptops. no disconnects that i can see but when i reboot the router, everything's lovely again for 48 hours or so,

when i made the leap, i thought i did do 2 full resets but they didn't take. rtm on how to "truly" reset the box and it finally worked; but only did that once. the 5g band seems to be just a tad weaker as well.

haven't done any g2 per se as i'm still lovin' on the merlin feats in this code. will post again once i have something to report. so for now, this is simply an fyi.

Suggest you restore Asus code and see if the problem is gone for a week. If gone then install Merlin to see if the problem returns.

 

[sbsnb]

Suggest you restore Asus code and see if the problem is gone for a week. If gone then install Merlin to see if the problem returns.

His nodes are running Asus stock firmware. The probability of all three routers having the same problem simultaneously is extremely remote. There is likely an external factor.

I don't know how OP determined that there are no sources of interference, but I would check very thoroughly using something that can detect hidden APs. I'm not sure if site scan is capable. There are several free apps for smartphones to scan WiFi that can work, or inSSIDer for a laptop. Could be a new printer or other device that unexpectedly has a built-in AP.

 

[Morris]

His nodes are running Asus stock firmware. The probability of all three routers having the same problem simultaneously is extremely remote. There is likely an external factor.

Interference is a common cause of slowdowns on the 2.4 Ghz band that frequently causes symptoms that have been reported by all 3 individuals. They need to take steps to prove the issue is not interference as described earlier in this thread. For those blaming the Merlin firmware they need to return to stock and not have the problem for an extended period or go back to a version of Merlin that they feel was not causing the problem. After not having the problem for at least a week, returning to the current release and having problems again would be interesting.

 

[RangerZ]

From a voyer perspective, it appears you all have done dirty upgrades and not yet reset. Unclear where @128bit is at.
FWIW, I installed a set of CT8s and 2.4 was lousy, before and after upgrading. Full reset of both devices fixed it.
See this link, for all kinds of good stuff and a nuclear reset option.
Merlin also has a great guide that covers this and his suggested config, but I can not put my hands on it ATM. It's in another thread.
Please also see the first FAQ under General Options about Wireless

 

[Pergola Fabio]

I do always WPS resets, so that's not the issue...

 

[RangerZ]

I do always WPS resets, so that's not the issue...

So, we can see how that's working out for ya.

If you read the nuclear option you will see that you are NOT doing all of the things that you could do to for a router with problem