RT-AX86U random reboots

[Tommy Grace]

Hi Guys

Had an RT-AX86U for well over a year and it's been rock solid. All of a sudden just over a week ago it rebooted (albeit very quickly) for no apparent reason. It had done this previously but during the heatwave so i assumed it was overheating as it soon stopped. Anyway it has started to happen more frequently, almost on a daily basis. When it started it was running 3.0.0.4.386.49599 so i tried going to Merlin 386.7_2 which it is currently on. It is still happening and i can't see anything useful in the logs at all. I haven't done a factory reset yet but was wondering if that is the next thing to try or not? If so, should i rebuild from scratch or try and upload my backup config?

Thanks
Tom

 

[bbunge]

Hi Guys

Had an RT-AX86U for well over a year and it's been rock solid. All of a sudden just over a week ago it rebooted (albeit very quickly) for no apparent reason. It had done this previously but during the heatwave so i assumed it was overheating as it soon stopped. Anyway it has started to happen more frequently, almost on a daily basis. When it started it was running 3.0.0.4.386.49599 so i tried going to Merlin 386.7_2 which it is currently on. It is still happening and i can't see anything useful in the logs at all. I haven't done a factory reset yet but was wondering if that is the next thing to try or not? If so, should i rebuild from scratch or try and upload my backup config?

Thanks
Tom

Factory reset with initialize is a good starting point. Hard Factory Reset is also good but may not always work. You might also try the 388 beta for the AX86U. And check the power supply voltage.

 

[Tommy Grace]

Factory reset with initialize is a good starting point. Hard Factory Reset is also good but may not always work. You might also try the 388 beta for the AX86U. And check the power supply voltage.

OK thanks, was a bit sceptical of trying the Beta firmware but happy to give it a go. Are many out there using it?

 

[bbunge]

OK thanks, was a bit sceptical of trying the Beta firmware but happy to give it a go. Are many out there using it?

Hard to tell how many. There are few reports of problems but I feel those are operator error. Most like me are well pleased with the beta!

 

[Tommy Grace]

Hard to tell how many. There are few reports of problems but I feel those are operator error. Most like me are well pleased with the beta!

OK thanks, will give that a go first i think. Then factory reset failing that.

 

[ColinTaylor]

Your first port of call should be to check the System Log for clues as to why it rebooted. You said there wasn't anything useful there but context can sometimes provide clues.

If you're on Merlin's firmware you can monitor the temperatures if you think that might be the problem.

 

[bbunge]

OK thanks, will give that a go first i think. Then factory reset failing that.

Ah... factory reset every time you change firmware!

 

[IcecreamVille]

Long time lurker, first time poster.

I'm experiencing a similar reboot issue - but it is more of a reboot loop. I can recreate instances where it reboots, but don't see anything in the log (not using log server) that indicates issue.

Main router uses 1 Gig WAN port & has a portable USB drive plugged in. Merlin 386.7_2.

Scenarios where reboot loop occurs:

I hooked up an RT-ACA68U as a media bridge. Had 2 Ethernet cables plugged in. One of the cables didn't have a device plugged into it. Leaving this cable plugged in while not connected on the other end would cause the RT-AX86U to reboot continually. When I unplugged the cable, problem went away.

Another scenario is when I was looking at my AiMesh nodes (Main router RT-AX86U. Nodes = models RT-AX86U, RT-AC86U, RT-AC68U)

I was looking at AiMESH topology & one of my RT-AC86U units was connected to another node. So I changed preferred node to be the main router. Reboot loop commences & would not stop until I powered off the RT-AC86U. The RT-AC86U did have something plugged into an Ethernet port (and was plugged into the other end).

I'm baffled by both of these scenarios because I can't understand why the main router would reboot - I'm guessing there is some sort of error code/condition that is being treated as a terminal error & causing the reboots.

Thanks

 

[Tommy Grace]

Just a quick update. I did Factory reset with initialize and then uploaded my previous saved config and it’s been fine now for nearly 8 days with no issues at all. Fingers crossed it stays this way. I’m on Merlin 386.7_2.

 

[IcecreamVille]

This is just an update on the response that I made earlier (Tommy, glad your issue is resolved).

I had mentioned that I came across 2 scenarios where the reboot happened.

I then started a new thread discussing the AiMesh issue - which turns out doesn't just happen with AiMesh (https://www.snbforums.com/threads/rt-ax86u-reboot-loop-issue-when-adding-aimesh-node.80790/)

With the RT-AC86U completely off the network, I plugged an Ethernet cable into one of the LAN ports of the RT-AC68U used as a media bridge, with the other end not plugged in, which I stated was one of the reboot scenarios. Rebooting did not happen - so I suspect that was just coincidence & the RT-AC86U was responsible for the rebooting, as that was on the network when I first reported this scenario.

Just wanted to report new findings & not spread misinformation.

 

[breadlord]

Hey all - new here and seeing the same issue. I've dug out the most recent crash logs and I believe it may be due to hosts that supoport IPv6 making requests of a router that has them disabled:

...

May  5 06:05:08 crashlog: <2>CPU2: stopping
May  5 06:05:08 crashlog: <4>CPU: 2 PID: 0 Comm: swapper/2 Tainted: P           O L  4.1.52 #2
May  5 06:05:08 crashlog: <4>Hardware name: Broadcom-v8A (DT)
May  5 06:05:08 crashlog: <0>Call trace:
May  5 06:05:08 crashlog: <4>[<ffffffc000087398>] dump_backtrace+0x0/0x150
May  5 06:05:08 crashlog: <4>[<ffffffc0000874fc>] show_stack+0x14/0x20
May  5 06:05:08 crashlog: <4>[<ffffffc0005589d0>] dump_stack+0x90/0xb0
May  5 06:05:08 crashlog: <4>[<ffffffc00008d710>] handle_IPI+0x190/0x1a0
May  5 06:05:08 crashlog: <4>[<ffffffc000080c68>] gic_handle_irq+0x88/0x90
May  5 06:05:08 crashlog: <4>Exception stack(0xffffffc03e8cfdc0 to 0xffffffc03e8cfef0)
May  5 06:05:08 crashlog: <4>fdc0: b2bab4bc 000000c5 00000000 00000080 3e8cff10 ffffffc0 00381594 ffffffc0
May  5 06:05:08 crashlog: <4>fde0: b2bab4bc 000000c5 70134b50 004842b8 0306b051 00000000 1400007e 00000000
May  5 06:05:08 crashlog: <4>fe00: 0017650a 00000000 00000018 00000000 9ec88372 000bbcf0 c93ff75c 000000c5
May  5 06:05:08 crashlog: <4>fe20: 3e8c3a70 ffffffc0 3e8cfec0 ffffffc0 3e801248 ffffffc0 2883ff80 ffffffc0
May  5 06:05:08 crashlog: <4>fe40: 00000018 00000000 ff8dd940 00000000 f7483400 00000000 00000000 00000000
May  5 06:05:08 crashlog: <4>fe60: 003e31e8 ffffffc0 00000000 00000000 00000000 00000000 b2bab4bc 000000c5
May  5 06:05:08 crashlog: <4>fe80: 3ffd4338 ffffffc0 00000001 00000000 00000001 00000000 b2b8a5a0 000000c5
May  5 06:05:08 crashlog: <4>fea0: 3e8cc000 ffffffc0 00919000 ffffffc0 00746000 ffffffc0 3ffd4338 ffffffc0
May  5 06:05:08 crashlog: <4>fec0: 00789300 ffffffc0 3e8cff10 ffffffc0 0038158c ffffffc0 3e8cff10 ffffffc0
May  5 06:05:08 crashlog: <4>fee0: 00381594 ffffffc0 60000145 00000000
May  5 06:05:08 crashlog: <4>[<ffffffc000083f00>] el1_irq+0x80/0xf8
May  5 06:05:08 crashlog: <4>[<ffffffc000381698>] cpuidle_enter+0x18/0x20
May  5 06:05:08 crashlog: <4>[<ffffffc0000c5e5c>] cpu_startup_entry+0x1ec/0x250
May  5 06:05:08 crashlog: <4>[<ffffffc00008d190>] secondary_start_kernel+0x150/0x178
May  5 06:05:08 crashlog: <4>SMP: failed to stop secondary CPUs
May  5 06:05:08 crashlog:
May  5 06:05:08 crashlog:
May  5 06:05:08 crashlog:
May  5 06:05:08 crashlog:
May  5 06:05:08 crashlog:
May  5 06:05:08 kernel: ^[[0;33;41m[ERROR pktrunner] runnerUcast_inet6addr_event,148: Could not rdpa_system_ipv6_host_address_table_find ret=-5^[[0m

I suspect that what's happening is that a newer host (Probably my work mac, running Monterey, and my Windows 10 PC, doing all kinds of crazy network stuff) are sending out IPv6 multicast packets - as a guess they might be mDNS over IPv6. Looks like the router has some kernel code to handle them, but it's not being processed, so is causing a lockup, which is health-checked into a reboot

 

[cwl999]

I've been running a new ax86S for the last 4 days and it's self rebooted twice already. Firmware 3.0.0.4.386_49599-g8352df7
Only intersting thing in logs is

May 5 06:05:04 kernel: print_rst_status: Last RESET due to SW reset
May 5 06:05:04 kernel: print_rst_status: RESET reason: 0x00000000

I may have to do a full factory reset on the beta firmware

 

[L&LD]

Welcome to the forums @cwl999.

Yes.

 

[Tommy Grace]

Just a quick update. I did Factory reset with initialize and then uploaded my previous saved config and it’s been fine now for nearly 8 days with no issues at all. Fingers crossed it stays this way. I’m on Merlin 386.7_2.

Spoke to soon. It’s started again over the last couple of day much to my annoyance.

 

[Log]

I am in the similar random reboot mode in AX86U for last 2-3 weeks. after messing with everything I could, last night I went back to 386.5_2 and have been stable for 24 hours now. I did try the latest Asus fw from 9/30/22 as well as Merlins last few updates including current beta. Something is fk'd up with last few FW's out there both Merlin/Asus and logs have not indicated a pattern either.. I also tried using the most basic router setup, no VPN no fancy options just the most basic functionality like wifi and ddns and that's about it.

 

[cwl999]

Since I disabled AiProtection, the reboots have not reoccurred and uptime is 14 days. I'm on the current stable firmware with almost everything stock.

 

[OzarkEdge]

Just a quick update. I did Factory reset with initialize and then uploaded my previous saved config and it’s been fine now for nearly 8 days with no issues at all. Fingers crossed it stays this way. I’m on Merlin 386.7_2.

Restoring fw settings from a .cfg file defeats the Reset/Hard Reset when trying to establish a baseline for troubleshooting.

Reset FAQ
Reset button/webUI Restore/node removal - clears settings in NVRAM; reboot restores fw defaults from CFE (fw defaults)
Hard Reset via WPS button/webUI Restore+Initialize - also clears data logged in /jffs partition (fw defaults+clear logs)

I would Hard Reset and configure minimally from scratch. Then proceed incrementally from there, allowing time for the issue to resurface.

Also consider disconnecting everything (or one by one) from the router ports except the WAN and your trusted admin LAN client... sometimes hard faults on connected devices can trouble a router including a failing AC/DC power adapter.

OE

 

[Theodore]

Since I disabled AiProtection, the reboots have not reoccurred and uptime is 14 days. I'm on the current stable firmware with almost everything stock.

I created a forum account to reply to this thread. I've been troubleshooting this issue on both Asus and Merlin firmware. The issue was most noticeable when my family was using devices that are covered under some of the protection group rules. The router is stable when they are not using their devices. In the past few hours, it rebooted seven times in a row, until I disabled aiprotection. It's been stable since.

I wish the logs were more conclusive, they only show kernel errors in blocking.asp and then the start of the boot up sequence. I'd probably need to involve support to get a memory dump, but I don't want to take the time. Going to flash the latest Asus firmware and do another factory reset.

 

[Clogger]

Have had the same problem with RT-AX86S, random reboots with no apparent reason. System log of no help. Prior to this running without any problem for 6 weeks.

Tried several things troubleshooting, and since I disconnected an external hard drive from the USB 3.0 port the router has been running solid for the last week.

Might be that the external hard drive put to much strain on the power supply, as it did not have a power supply of its own, thereby making the router reboot. Might be something to consider if you have an external hard drive connected.

 

[polanskiman]

I've had the exact same issue on the exact same router (RT-AX86U) with the exact same firmware (386.7_2). To this day I haven't figured out what is causing it. I have no HD attached to it and AIProtection is disabled, so those are definitely not the issue, for me at least.

In fact I have 2 units, both configured very similarly. The one in my home doesn't do this as far as I know. The one in my office however does it nearly every day and interestingly at nearly the same time. Logs don't show any meaningful error prior reboot. Sometimes I do see some WAN disconnects prior the reboot but those are usually several minutes prior reboot and they do not occur each time so it is difficult to point the finger at it. Both units are run with APC UPSes, so juice is clean and stable.