RT-AX82U dropping connection

[demirari]

Hi there,

I have an RT-AX82U as a router running firmware 3.0.0.4.386_45375. Merlin is not available for this device. I am also running a Pi-hole on the network however I have been doing so for some time without issue.

In the last few weeks, I have been experiencing drops in internet connection approximately once everyone few days. Devices remain connected to the router but cannot access the internet. Prior to this, I've not had issues which leads me to think a firmware update has caused these problems. The latest firmware was released on 2021/09/01 and I manually updated not too long after this date.

My current temporary solution is to reboot the router and connectivity is then restored fully for a few days until it drops again.

I have 160MHz enabled, internet detection is via DNS probe (although was previously PPP Echo and still caused issues) - please let me know if there are any other settings that may help.

Using the 'diagnostic tool' on the ASUS mobile apps shows modem connection issues. However I do not touch the modem, only reboot the router, which leads me to think it's a router problem. I have a Genexis fibre modem.

I can attach the system log showing the most recent drop taking place this morning (27 September) if that would help.

There are a number of things in the log I'm not clear on and would very much appreciate some guidance with, for example:

Sep 27 01:59:17 out of memory [1732]

Sep 27 02:04:22 check_watchdog: [check_watchdog] restart watchdog for no heartbeat
Sep 27 02:04:22 rc_service: check_watchdog 1353:notify_rc restart_watchdog

Sep 27 02:24:32 dnsmasq-dhcp[1308]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)

These items look to be the cause of the problems with potentially a memory leak occurring somewhere which causes the whole thing to collapse.

I'm tempted to roll back the firmware to Version 3.0.0.4.386.43129 however I thought I'd check if anyone has any alternative fixes before doing so?

Thanks for your time.

 

[Mr Tvardovsky]

If you feel brave, you can also consider giving a chance to the newest beta firmware:

Beta - ASUSWRT 386 RC3-1 public beta

Hi All, After waiting a long time, ASUSWRT is going to upgrade from 386 rc2 to 386 rc3. What's new in 386 RC3-1 New VPN client interface Clients can be assigned to a specific VPN profile. This function is similar to VPN fusion. (AX models' features) Support WirdGuard server and client. (AX...

www.snbforums.com

 

[benjiking]

Hi there, I signed up specifically to respond to this.
I have the same model, same symptoms, and I agree it appears to be firmware-related.

 

[demirari]

If you feel brave, you can also consider giving a chance to the newest beta firmware:

Beta - ASUSWRT 386 RC3-1 public beta

Hi All, After waiting a long time, ASUSWRT is going to upgrade from 386 rc2 to 386 rc3. What's new in 386 RC3-1 New VPN client interface Clients can be assigned to a specific VPN profile. This function is similar to VPN fusion. (AX models' features) Support WirdGuard server and client. (AX...

www.snbforums.com

Thanks for the suggestion, I'm not sure I can afford to be brave else my household will riot if it falls over!

Hi there, I signed up specifically to respond to this.
I have the same model, same symptoms, and I agree it appears to be firmware-related.

I also signed up to post my original question.

Since that post I've set up a scheduled reboot in the ASUS app to take place every other day at 3am. I hope this clears out whatever issues there might be before it requires a manual reboot. It's a little early to tell if this has worked but I'll report back in a week or so with an update.

I will also inform ASUS of this issue with the most recent patch in the hope a fix can follow.

 

[benjiking]

Unfortunately, I am already doing a scheduled reboot three times a week and confirm this does not resolve the issue. It also started happening after the router updated its firmware this month. I cannot run the beta due to my work-from-home position.
If there is any way to alert ASUS of the problem for notoriety, please let me know, and I will do so as well.

 

[Plutootje]

Same problem overhere. Glad to read this post, as I suspected the modem causing this problem.
I will downgrade to version 3.0.0.4.386.43588 (2021/07/29).

 

[Mr Tvardovsky]

Guys, recently I had a chance to put my hands on a very cheap AX82U and as much as I love my Merlin-powered AC86U, I couldn’t resist playing with WiFi 6, 160 mHz, DFS etc. Shortly speaking, for a while the AX82U is my main router now.

Now, I’m running the same version of stock firmware as you all do and things are working fine so far. The connection is stable and the speeds are as expected. So honestly, I wouldn’t completely exclude issues related to factors other than firmware.

BTW, during the weekend I am going to give a chance to the latest beta. I will let you know if anything interesting happens.

 

[Plutootje]

As Demirari said: It occurs every few days or week.

Yesterday evening I downgraded to 3.0.0.4.386.43588. I'll keep you posted about the status.

 

[Markymarc]

Hi there, I signed up specifically to respond to this.
I have the same model, same symptoms, and I agree it appears to be firmware-related.

Hiya,

another user here, this has been doing my head in for weeks now, I’ve been searching the internet to try to solve this, after many resets I’ll wait for a firmware update. I cannot afford to be on beta software either, hopefully the wait won’t be long.

 

[Plutootje]

Hiya,

another user here, this has been doing my head in for weeks now, I’ve been searching the internet to try to solve this, after many resets I’ll wait for a firmware update. I cannot afford to be on beta software either, hopefully the wait won’t be long.

You may consider downgrading (pending the release of the new firmware) to the previous firmware 3.0.0.4.386.43588.

 

[Markymarc]

You may consider downgrading (pending the release of the new firmware) to the previous firmware 3.0.0.4.386.43588.

Giving that a go now, hopefully it will be stable again.

thanks

 

[daniasdf]

hello everyone,

Same as some of the posters above me, I have just registered to SNB so I can contribute to this thread.
Bought this router a few weeks ago, updated it to the latest firmware, configured it to my needs and expected to be worthy of the money spent on it.

It worked fine for a week maybe, then the internet connection dropped.
I logged in and checked the status, indeed the connection to the modem dropped.

In the logs I was able to see that every 8 minutes it checks if there is a firmware update (auto update is disabled btw).
There are also messages about tainted kernel and that watchdog failure, clearly an indication that something got corrupted.

Started to investigate what could be the source of the problem.
Also configured auto reboot every night at 5AM as a workaround.
3 days ago the reboot did not happen.

After that I have disabled the Traffic Analyzer for which many users reported problems.
Don't really need it, just nice to have.

Read reports for other Asus routers that AiProtection and Web&Apps Filters from TrendMicro were causing problems.
I would like to keep using that feature as I find it useful for protecting my family.
But this is going to be my next attempt to isolate the feature causing the problem.

After that I will roll back to the previous firmware version.

I don't use any of the following features: AiMesh, AiCloud, Adaptive QoS, Game Accelerator, Web History, no USB device attached, VPN, IPv6.

 

[techwhisperer]

I had to downgrade the firmware as well. Usually ASUS is pretty solid with their firmware. I did open a support ticket with them as well. Hopefully they will fix it soon, as the latest firmware had a lot of security fixes in it.

 

[instigatorSF]

I too was having a similar problem after the latest firmware update. WAN connectivity would suddenly disappear because the RT-AX82U could not successfully acquire and maintain an IP address via DHCP from my ISP, Sonic.

My router was set to auto-reboot every week and the problem seemed to occur right after the startup. So, I turned off auto-reboot. Yet, the problem persisted.

After researching here and elsewhere where the problem was attributed to TrendMicro/Asus value add features, i tried turning of AI-related functionality. The problem continued to occur.

Finally, I noticed that of those that had also found this to be a DHCP-related issue, changing the "DHCP query frequency" seemed to help some. So, I changed my setting to "Continuous Mode."

Since I changed this setting, with everything the same as my original configuration (AI-etc. enabled) the problem has not occurred for over 10 days.

I hope this helps.

 

[Mr Tvardovsky]

Okay, after a week of reasonably stable behavior, my RT-AX82U developed a hiccup, too. I never lost my WAN connection, but occasionally the devices on my network stop "seeing" each other and in the GUI I can only see the router and the AiMesh nodes. Rebooting helps, waiting it out also does - but this is not an option in the middle of a work-from-home day.

I agree with @instigatorSF that the issue seems to be DHCP related. Whenever such event occurs, my System Log is getting full of such entries:

Sep 30 11:21:21 dnsmasq-dhcp[8525]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)

I wonder if one of the senior forum members could kindly take a look at this and tell us what it means?

In any case, @ASUSWRT_2020 , are you reading this?

In the meantime, I am loading up the new beta for the weekend and changing the "DHCP query frequency" into "Continuous Mode."

 

[techwhisperer]

Okay, after a week of reasonably stable behavior, my RT-AX82U developed a hiccup, too. I never lost my WAN connection, but occasionally the devices on my network stop "seeing" each other and in the GUI I can only see the router and the AiMesh nodes. Rebooting helps, waiting it out also does - but this is not an option in the middle of a work-from-home day.

I agree with @instigatorSF that the issue seems to be DHCP related. Whenever such event occurs, my System Log is getting full of such entries:

Sep 30 11:21:21 dnsmasq-dhcp[8525]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)

I wonder if one of the senior forum members could kindly take a look at this and tell us what it means?

In any case, @ASUSWRT_2020 , are you reading this?

In the meantime, I am loading up the new beta for the weekend and changing the "DHCP query frequency" into "Continuous Mode."

Where is the new beta?

 

[Mr Tvardovsky]

Where is the new beta?

Beta - ASUSWRT 386 RC3-1 public beta

Hi All, After waiting a long time, ASUSWRT is going to upgrade from 386 rc2 to 386 rc3. What's new in 386 RC3-1 New VPN client interface Clients can be assigned to a specific VPN profile. This function is similar to VPN fusion. (AX models' features) Support WirdGuard server and client. (AX...

www.snbforums.com

 

[demirari]

I too was having a similar problem after the latest firmware update. WAN connectivity would suddenly disappear because the RT-AX82U could not successfully acquire and maintain an IP address via DHCP from my ISP, Sonic.

My router was set to auto-reboot every week and the problem seemed to occur right after the startup. So, I turned off auto-reboot. Yet, the problem persisted.

After researching here and elsewhere where the problem was attributed to TrendMicro/Asus value add features, i tried turning of AI-related functionality. The problem continued to occur.

Finally, I noticed that of those that had also found this to be a DHCP-related issue, changing the "DHCP query frequency" seemed to help some. So, I changed my setting to "Continuous Mode."

Since I changed this setting, with everything the same as my original configuration (AI-etc. enabled) the problem has not occurred for over 10 days.

I hope this helps.

I don't appear to have the ability to set DHCP query frequency. To confirm, this should be within WAN - Internet Connection - Special Requirements from ISP?

My ASUS support ticket has so far only proposed a factory reset of the router, but this isn't helping. I'll revert and see if they can address a more specific fix. I've already directed them to this thread.

I'm rebooting each night too and this was working for a few days however I've had another drop out today.

I will probably be rolling back firmware in the next few days pending a fix in the next update.

 

[Mr Tvardovsky]

I don't appear to have the ability to set DHCP query frequency. To confirm, this should be within WAN - Internet Connection - Special Requirements from ISP?

Yes:

 

[Mr Tvardovsky]

Hi Guys, did you upgrade to the latest stable version (as per my signature below)? Two days uptime and so far so good for me.