Asus RT-AX86U stopped working occasionally

[wmd1942]

I have had my RT-AX86U with Merlin (latest firmware 3004.388.9_2) running for a few years. Recently, it has occasionally stopped working completely, and this issue recurred today. I noticed the problem around 1:10 pm. No DHCP, no internet, no ssh, and it was back to its normal working state after power cycled. I took a look at the syslog and noticed the issue started at 12:54:06 am this early morning. The timestamp was changed to December 31 suddenly. The timestamp was recovered at 12:54:55, but the syslog stopped at 12:55:22. Any help is greatly appreciated.


Sep 13 12:54:05 rc_service: watchdog 1650:notify_rc start_dnsmasq
Sep 13 12:54:05 custom_script: Running /jffs/scripts/service-event (args: start dnsmasq)
Sep 13 12:54:05 custom_script: Running /jffs/scripts/dnsmasq.postconf (args: /etc/dnsmasq.conf)
Sep 13 12:54:06 Diversion: restarted Dnsmasq to apply settings
Sep 13 12:54:06 stubby[18216]: Read config from file /etc/stubby/stubby.yml
Sep 13 12:54:06 stubby[18216]: Stubby version: Stubby 0.4.2
Sep 13 12:54:06 dnsmasq[18218]: cannot open log /opt/var/log/dnsmasq.log: Read-only file system
Sep 13 12:54:06 dnsmasq[18218]: FAILED to start up
Dec 31 19:00:25 syslogd started: BusyBox v1.25.1
Dec 31 19:00:25 kernel: klogd started: BusyBox v1.25.1 (2025-04-28 17:28:04 EDT)
Dec 31 19:00:25 kernel: Booting Linux on physical CPU 0x0
Dec 31 19:00:25 kernel: Linux version 4.1.52 (merlin@ubuntu-dev) (gcc version 5.5.0 (Buildroot 2017.11.1) ) #2 SMP PREEMPT Mon Apr 28 17:48:56 EDT 2025
Dec 31 19:00:25 kernel: CPU: AArch64 Processor [420f1000] revision 0
Dec 31 19:00:25 kernel: Detected VIPT I-cache on CPU0
Dec 31 19:00:25 kernel: alternatives: enabling workaround for ARM erratum 845719
Dec 31 19:00:25 kernel: On node 0 totalpages: 248064
Dec 31 19:00:25 kernel: DMA zone: 3584 pages used for memmap
Dec 31 19:00:25 kernel: DMA zone: 0 pages reserved
Dec 31 19:00:25 kernel: DMA zone: 248064 pages, LIFO batch:31
Dec 31 19:00:25 kernel: PERCPU: Embedded 15 pages/cpu @ffffffc03ffb3000 s21400 r8192 d31848 u61440
Dec 31 19:00:25 kernel: pcpu-alloc: s21400 r8192 d31848 u61440 alloc=15*4096
Dec 31 19:00:25 kernel: pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3
Dec 31 19:00:25 kernel: Built 1 zonelists in Zone order, mobility grouping on. Total pages: 244480
Dec 31 19:00:25 kernel: Kernel command line: root=ubi:rootfs_ubifs ubi.mtd=0 rootfstype=ubifs coherent_pool=4M cpuidle_sysfs_switch pci=pcie_bus_safe rootwait
Dec 31 19:00:25 kernel: PID hash table entries: 4096 (order: 3, 32768 bytes)
Dec 31 19:00:25 kernel: Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes)
Dec 31 19:00:25 kernel: Inode-cache hash table entries: 65536 (order: 7, 524288 bytes)
Dec 31 19:00:25 kernel: Memory: 933732K/992256K available (5034K kernel code, 1855K rwdata, 1692K rodata, 232K init, 553K bss, 58524K reserved, 0K cma-reserved)
... ... ...

Dec 31 19:00:36 wlceventd: wlceventd_proc_event(685): eth6: Auth XX:XX:XX:XX:XX:XX, status: Successful (0), rssi:0
Dec 31 19:00:36 custom_script: Running /jffs/scripts/service-event (args: start ntpd)
Dec 31 19:00:36 ntpd: Started ntpd
Dec 31 19:00:36 hostapd: eth6: STA XX:XX:XX:XX:XX:XX IEEE 802.11: associated
Dec 31 19:00:36 kernel: sda: sda1
Dec 31 19:00:36 wlceventd: wlceventd_proc_event(722): eth6: Assoc XX:XX:XX:XX:XX:XX, status: Successful (0), rssi:-27
Dec 31 19:00:36 kernel: sd 0:0:0:0: [sda] Attached SCSI removable disk
Dec 31 19:00:36 hostapd: eth6: STA XX:XX:XX:XX:XX:XX RADIUS: starting accounting session 5CAFA965FFBFD0DA
Dec 31 19:00:36 hostapd: eth6: STA XX:XX:XX:XX:XX:XX WPA: pairwise key handshake completed (RSN)
Sep 13 12:54:55 ntpd: Initial clock set
Sep 13 12:54:55 rc_service: ntpd_synced 2276:notify_rc restart_stubby
Sep 13 12:54:55 rc_service: ntpd_synced 2276:notify_rc restart_diskmon
Sep 13 12:54:55 rc_service: waitting "restart_stubby" via ntpd_synced ...
Sep 13 12:54:55 custom_script: Running /jffs/scripts/service-event (args: restart stubby)

... ... ... ...

Sep 13 12:55:19 networkmap: Error locking /var/lock//usr/networkmap/nmp_conv_type.js.lock: 2 No such file or directory
Sep 13 12:55:19 networkmap: Error unlocking -1: 9 Bad file descriptor
Sep 13 12:55:19 networkmap: Error locking /var/lock//usr/networkmap/nmp_vendor_type.js.lock: 2 No such file or directory
Sep 13 12:55:19 networkmap: Error unlocking -1: 9 Bad file descriptor
Sep 13 12:55:19 networkmap: Error locking /var/lock//usr/networkmap/nmp_bwdpi_type.js.lock: 2 No such file or directory
Sep 13 12:55:19 networkmap: Error unlocking -1: 9 Bad file descriptor
Sep 13 12:55:22 YazFi: YazFi v4.4.4 completed successfully
Sep 13 13:10:22 rc_service: service 2648:notify_rc stop_vpnclient1
Sep 13 13:10:22 custom_script: Running /jffs/scripts/service-event (args: stop vpnclient1)
Sep 13 13:10:22 ovpn-client1[2818]: event_wait : Interrupted system call (fd=-1,code=4)
Sep 13 13:10:22 ovpn-client1[2818]: ovpn-route-pre-down tun11 1500 0 10.16.0.15 255.255.0.0 init
Sep 13 13:10:22 custom_script: Running openvpn-event
Sep 13 13:10:22 ovpn-client1[2818]: Closing TUN/TAP interface
... ... ... ...

 

[ColinTaylor]

Sep 13 12:54:06 dnsmasq[18218]: cannot open log /opt/var/log/dnsmasq.log: Read-only file system

Your USB drive has failed and gone into read-only mode. Replace it and reinstall your custom scripts (or disable custom scripts in Administration - System).

 

[bennor]

The timestamp was changed to December 31 suddenly.

That is typically an indicator of the router/firmware (or a core service) rebooting. It shows that date until it polls the NTP server and sets the time on the router.

It would help if you listed all the addon scripts you are running since it appears you are running at least Diversion. And I assume you have a USB drive attached as well?

Does the router exhibit the issue you are reporting if you remove any and all addon scripts? And or if you reset the router to default settings and not install any addon scripts? Does the issue persist if you remove any attached USB drive?