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ASUS RT-AC88U 5GHz network connection drops after a few minutes, does not recover

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dotzak

Occasional Visitor
I'm using a fairly new (purchased about a month ago) ASUS RT-AC88U router.

Since configuring it the 5GHz connection drops a few minutes after restarting the router—it no longer appears when scanning for networks, currently connected devices lose their connection to the internet and then the network. Restarting reenables the network for a short amount of time, but within 5-30 minutes it will drop again.

The 2.4GHz network is unaffected.
  • I've reset the router to factory defaults and the problem persists.
  • This morning (2016-08-08) I updated the firmware (v 3.0.0.4.380_3941-g27d8adf) and the problem persists.
  • Typically there are around 12 clients, maximum is about 18.
  • As I was writing this post the whole thing dropped all connections (2.4GHz and 5.5Ghz) and I plugged in an ethernet cable and couldn't connect. The entire event was about 1 minute.
I don't know where to start troubleshooting this issue. I was hoping somebody could point me in the right direction.
 
I'm going to attach a log file here if someone thinks that will help.

The NTP server seems to be a problem. Note that this is plugged into a modem which requires some static setup (IP/Subnet/Gateway, DNS).
 

Attachments

  • syslog.txt
    39.6 KB · Views: 1,306
I'm using a fairly new (purchased about a month ago) ASUS RT-AC88U router.

Since configuring it the 5GHz connection drops a few minutes after restarting the router—it no longer appears when scanning for networks, currently connected devices lose their connection to the internet and then the network. Restarting reenables the network for a short amount of time, but within 5-30 minutes it will drop again.

The 2.4GHz network is unaffected.
  • I've reset the router to factory defaults and the problem persists.
  • This morning (2016-08-08) I updated the firmware (v 3.0.0.4.380_3941-g27d8adf) and the problem persists.
  • Typically there are around 12 clients, maximum is about 18.
  • As I was writing this post the whole thing dropped all connections (2.4GHz and 5.5Ghz) and I plugged in an ethernet cable and couldn't connect. The entire event was about 1 minute.
I don't know where to start troubleshooting this issue. I was hoping somebody could point me in the right direction.

Is it running too hot by any chance? I have little brother RT-AC3100 which is running rock solid. Is the radio going off the air? Log has an entry 'ISP DHCP did not work properly' there.
 
Is it running too hot by any chance? I have little brother RT-AC3100 which is running rock solid. Any chance to look at the log?

Hi Tony, thanks for the response.

I was worried about the heat, too, so I've moved it to a new location but the problem persists. It's in a pretty cool location at the moment and should be within the manufacturer standards (it's in the office on a table in a corner, not in a hutch or cabinet or anything).

I've attached a log in my last reply on this thread.
 
check first, your internet connection without router.

if internet is solid, change the cable between modem and router.

and you can also test with other adapter which matched proper V and A ex) laptop adapter
 
check first, your internet connection without router.

if internet is solid, change the cable between modem and router.

and you can also test with other adapter which matched proper V and A ex) laptop adapter

That's an interesting diagnostic, I'll try it out after work hours. Though I'm skeptical as I'm not sure that I understand why the cable would affect one wireless network but not the other.
 
On a separate note, on a whim (kinda just trying anything at this point) I went to the Wireless > Wireless - General panel and switched Wireless Mode from "Auto" to "N/AC mixed" and I have yet to get a drop in about 2 hours.

This was based on some random user in some random thread's comment. I didn't expect it to do anything, but it seems to have done the trick. Weird. I'm going to monitor it and will respond either way.
 
Did you fully reset the router after updating to the latest firmware version (and no use of backups to restore settings) ?
I am running an AC88U here and its rock solid on connections.
Possible hardware problems? Does it operate in a warm environment?
 
Did you fully reset the router after updating to the latest firmware version (and no use of backups to restore settings) ?
I am running an AC88U here and its rock solid on connections.
Possible hardware problems? Does it operate in a warm enviroment?

Yes, before I posted (earlier this morning) I updated to the latest firmware and reset the router. I'm suspecting a possible hardware failure, but I'm not willing to confirm that, yet. Re: heat, I don't think that heat is the culprit in this case. It does sound like a heating problem, but realistically it's not in that hot of an environment (especially during operating hours when it's in an air-conditioned room).
 
Another test to perform is to selectively connect each client - one by one
This is to verify that the issue is not linked to a specific device breaking the connection and hanging the router.

Also, have you given different SSID names to the 2.4Ghz and 5Ghz?
 
On a separate note, on a whim (kinda just trying anything at this point) I went to the Wireless > Wireless - General panel and switched Wireless Mode from "Auto" to "N/AC mixed" and I have yet to get a drop in about 2 hours.

This was based on some random user in some random thread's comment. I didn't expect it to do anything, but it seems to have done the trick. Weird. I'm going to monitor it and will respond either way.

Also don't use auto channel selection.
 
Another test to perform is to selectively connect each client - one by one
This is to verify that the issue is not linked to a specific device breaking the connection and hanging the router.

This is quite difficult to do as it's an office environment so everyone is either in or out at pretty much the same time each day.

Also, have you given different SSID names to the 2.4Ghz and 5Ghz?

Yes. They're similar, but unique.
 
Also don't use auto channel selection.

I've disabled that but it really hasn't improved anything. To be honest, it looks like switching the Wireless Mode was probably just placebo. It didn't seem like a useful recommendation and it didn't really fix the issue.

EDIT: accidentally wrote "did" instead of "didn't".
 
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I've disabled that but it really hasn't improved anything. To be honest, it looks like switching the Wireless Mode was probably just placebo. It didn't seem like a useful recommendation and it did really fix the issue.

I am having the same exact issue with my 5GHz band on my AC88U. I reached out to Asus support and had 3 rounds of back and forth and now they gave me an RMA to send it in. The router worked great (flawlessly) for 2 1/2 weeks. Then all of a sudden, no 5GHz can be found. The LED indicates its broadcasting and everything in the gui shows as if it's on, but nothing can find it to connect. Just like you, after a reboot it will show from anywhere from 1-15 minutes.

I'm confused by your last post. Are you saying what you recommended (change from auto to ac/n mix) did work and is still working for you?

I was excited last night when I stumbled on this thread and quickly tried your suggestion. However, the 5GHz only broadcast for 5 minutes then... Poof! Gone.

If that is now working for you, what are you other settings? I am hopeful this might help, as your description on the issue is the only exact match to the issue I have that I have found in my tireless research for a fix online.
 
Most router issues are due to settings and configuration problems or problems are related to configuration changes after a firmware update. I would try resetting the router again.

Disconnect all devices from the router except for WAN to modem Ethernet and LAN to computer cable. Power router off then on and wait for router to power up completely. Next while the router is powered on hold the reset button (push with pen tip) for at least ten seconds. Wait at least two minutes and then set router up manually like when it was new via computer to LAN cable using the web browser interface for admin setup. Don't upload old firmware configuration settings. Configure the router manually.

After fully configuring and confirming your internet connection works. Power off the router for ten seconds and then on again. Test your connections and your wireless 2.4Ghz and 5Ghz to make sure they are working. You could try resetting it again this same way if it doesn't work the first time but if it doesn't work after that then I would suspect a hardware issue. Post your final results here.
 
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Most router issues are due to settings and configuration problems or problems are related to configuration changes after a firmware update. I would try resetting the router again.

I would agree with you that this is typically the case. In this case the connection for 5GHz doesn't work at all, even if the only settings changed are the SSID and password.

Interestingly the 5GHz network will sometimes appear in the dropdown list of available networks, but connections to it fail. A couple of screenshots to show you what I mean, click here.

I'm assuming it's a hardware failure. Even with clean, up-to-date software with default config the 5GHz network fails and the 2.4GHz network underperforms.

Attached is a log file after today's restore (including firmware reinstall via ASUS Firmware Restoration utility for Mac), and a log from yesterday before the restore.
 

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  • syslog AFTER RESTORE.txt
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  • syslog BEFORE RESTORE.txt
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I would agree with you that this is typically the case. In this case the connection for 5GHz doesn't work at all, even if the only settings changed are the SSID and password.

Interestingly the 5GHz network will sometimes appear in the dropdown list of available networks, but connections to it fail. A couple of screenshots to show you what I mean, click here.

I'm assuming it's a hardware failure. Even with clean, up-to-date software with default config the 5GHz network fails and the 2.4GHz network underperforms.

Attached is a log file after today's restore (including firmware reinstall via ASUS Firmware Restoration utility for Mac), and a log from yesterday before the restore.
The fact that the 5Ghz radio is working at all makes me believe it's a firmware settings/configuration or conflict issue. I've seen similar 5Ghz problems where I saw the SSID but couldn't connect to it. I am not saying I had exactly the same issue but I have seen almost exactly the same issue with 5Ghz dropping, not being able to connect, having it appear and disappear randomly, etc. .

Updating the firmware to a later version and doing a full reset of the router solved those random issues ... I saw these radio issues with my N66u years ago and with one of my ac68p routers a few months ago. Physically mounting the router up higher and changing the channel settings also helped the 5Ghz signal strength and reliability. Good luck with whatever solution you choose.
 
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I had identical problems with my first AC5300. In my case 5G-2 disappeared. No factory restore helped and eventually 5G-1 disappeared too and never came back. Sent it back to ASUS and got a replacement unit. My second AC5300 died almost identically within 3 weeks, but this time it was 2.4G that started to malfunction (on and off, and eventually died completely). I sent it back again and got a refund as I didn't want the third unit that with die within a month... Wanted to buy something older (but reliable) like AC88U, but seeing your problems now and realizing that internals (CPU and chipsets) are almost identical I think it might be some kind of inherent design fault...
 
I have tried every combination of settings, reboots, resets, and reinstalling firmware to no avail. In fact the problem is getting worse. I am now experiencing issues with 2.4 using the same exact setting from when it worked flawlessly during the initial 2 weeks following purchase. I want to add that I have not added anything to my home in this period that would cause interference, and my property is large enough that my neighbors would not effect this either. I am inclined to think it is hardware and will be sending the unit back under the RMA Asus provided. For now I'm using my old trusty D-Link, which has never once given me a single issue. I had to upgrade since I recently moved to a large house and couldn't even detect the signal from the D-Link out by the pool house.

I really wanted this router to work. All the reviews gave it such praise, and the first 2 weeks I had it, I have got to say, it was the best router I have ever used. The signal was so good I could go anywhere on my 3 acres and still be on 5GHz. I hope this is an issue that only occurs with a small number of the AC88U routers.

Is there anyone out there that can comment on their long term use of the AC88U, and reliability of LAN, 2.4GHz and 5GHz all being rock solid?

I will update in 3-6 weeks when I recieve the router back from repair. (Fingers crossed!!!)
 

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