Recurrently losing internet connection using ASUS RT-AC66U

[Rayyes]

Hi,

From Google searches, I know this is a widely prevalent issue with multiple possible solutions. I've tried factory resetting, updating to the latest firmware, changing to the latest Merlin Firmware, rebooting everything and so far nothing has worked. I lose my internet connection on every device, LAN as well as WiFi.

I decided to create a thread as I am hoping that there is something in the server log that would strongly suggest what the issue at hand is. Unfortunately, I am not currently knowledgeable enough to interpret the system log accurately by myself. One thing that caught my eye was the following:

Aug 1 02:00:34 miniupnpd[550]: Listening for NAT-PMP/PCP traffic on port 5351
Aug 1 02:00:35 WAN_Connection: WAN was restored.
Aug 1 02:00:36 ntp: start NTP update
Jul 9 08:56:12 rc_service: ntp 542:notify_rc restart_diskmon
Jul 9 08:56:12 disk_monitor: Finish
Jul 9 08:56:12 rc_service: ntp 542:notify_rc restart_upnp
Jul 9 08:56:12 miniupnpd[548]: shutting down MiniUPnPd
Jul 9 08:56:12 miniupnpd[574]: HTTP listening on port 48429
Jul 9 08:56:12 miniupnpd[574]: Listening for NAT-PMP/PCP traffic on port 5351
Jul 9 08:56:12 disk_monitor: be idle

It seems to me that my router is randomly rebooting itself, but I have no idea why. Is it simply time to get a new router? Could the issue be elsewhere?

EDIT: I was unable to post my full system, it kept getting blocked by the forum. Not sure why. I seemingly can't attach it as an external file either. What am I doing wrong?

 

[ColinTaylor]

I don't see anything unusual in what you posted. It might be significant if seen in the context of the full log.

From Google searches, I know this is a widely prevalent issue with multiple possible solutions.

Don't always believe internet searches, it can just be an echo chamber.

The forum's anti-spam/anti-malware filter frequently prevents posting syslogs. Upload it to a file sharing site and link to it.

 

[Rayyes]

Thanks for your quick reply. Here is the file containing the syslog: https://we.tl/tXIjtbzjbM

It happened again just now and I immediately checked the router lights and it seemed to me like it was resetting itself.

Is it not unusual for the WAN to reset itself all of a sudden?

 

[ColinTaylor]

Thanks for the log. So it looks like your suspicion is correct and that the router is spontaneously restarting itself. This is not the same as just the WAN interface restarting.

That's not unheard of with the RT-AC66U's because they are one of the older models that tend to have been in service for quite a few years (and the build quality isn't that great). So it might just have come to the end of its life.

Before you replace it there are a couple of things you can try. Make sure that it's in a cool environment. If it overheats you will see this behaviour. Replace the mains power adaptor. Again, these become unstable with age and temperature. People have reported in these forums that their problems went away after replacing the adaptor.

 

[Rayyes]

Thanks a lot! I'll try doing that. What is it in the log that makes it clear to you that the router is spontaneously restarting itself?

 

[ColinTaylor]

It's more a case of what's not in the log. When the router restarts you're seeing this sort of thing:

Jul  8 17:25:23 dnsmasq-dhcp[818]: DHCPACK(br0) 192.168.1.94 90:cd:b6:cf:2c:d9
Jul  8 17:25:23 dnsmasq-dhcp[818]: not giving name localhost to the DHCP lease of 192.168.1.225 because the name exists in /etc /hosts with address 127.0.0.1
Aug  1 02:00:13 syslogd started: BusyBox v1.25.1
Aug  1 02:00:13 kernel: klogd started: BusyBox v1.25.1 (2018-04-08 14:04:33 EDT)
Aug  1 02:00:13 kernel: start_kernel
:
Jul  9 08:52:56 dnsmasq-dhcp[291]: DHCPACK(br0) 192.168.1.237 b4:ae:2b:cb:ae:9a Rayyes-Surface
Jul  9 08:52:56 dnsmasq-dhcp[291]: not giving name localhost to the DHCP lease of 192.168.1.225 because the name exists in /etc /hosts with address 127.0.0.1
Jul  9 08:52:59 miniupnpd[816]: upnp_event_recv: recv(): Connection reset by peer
Aug  1 02:00:13 syslogd started: BusyBox v1.25.1
Aug  1 02:00:13 kernel: klogd started: BusyBox v1.25.1 (2018-04-08 14:04:33 EDT)
Aug  1 02:00:13 kernel: start_kernel

If the router was rebooted in a controlled manner I'd expect to see quite a few lines prior to the "syslogd started: BusyBox v1.25.1" message showing various services being terminated.

That said, I remember in the past there issues with the way that the logs were stored on the N66U and AC66U which meant that sometimes the last part of the log was lost. I think they fixed that though. You can test that. Log in to the router's web interface and click the reboot button. When the router comes back up look at the syslog for any "terminating"-type messges at the time you did the reboot.

 

[Rayyes]

I see, thanks a lot. I've replaced the net adapter now and so far, it seems to have stabilized. It might be too soon to tell, however. Thanks for the help, it's been greatly appreciated.

 

[Rayyes]

So replacing the net adapter did not help. It's been worse than ever during the morning.

Any other suggestions? I will otherwise simply replace the router.

 

[coxhaus]

Have checked to make sure you are not have a power sag which resets the router? Maybe try a UPS?

I run a Cisco RV340 router and it runs without any reboots or requiring any reboots. Maybe try a small business router?