Oddly, my router Asus RT-AC68U has been fine for a long time and just started acting weird today also.
It suddenly dropped internet connectivity early afternoon PST. I logged into the router and it showed the LAN as fine but the WAN as disconnected even though the attached cabled modem was fine. I power cycled it and then it worked for a few hours before disconnecting again. So I power cycled it again and immediately went to look for a firmware update. I upgraded from 3.0.0.4.386_48262 to 3.0.0.4.386_51665 using the auto update (not manual). So it does appear that your firmware is behind. I wasn't sure if that would fix my issue so I started digging through the logs and found lots of similar errors:
Code:
May 17 18:51:32 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:51:41 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:51:41 dnsmasq[722]: script process exited with status 16
May 17 18:51:49 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:52:04 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:52:13 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:52:13 dnsmasq[722]: script process exited with status 16
May 17 18:52:47 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:52:47 dnsmasq[722]: script process exited with status 16
May 17 18:52:55 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:52:55 dnsmasq[722]: script process exited with status 16
May 17 18:53:07 syslog: wlceventd_proc_event(508): eth2: Disassoc CC:C0:79:57:58:E9, status: 0, reason: Disassociated because sending station is leaving (or has left) BSS (8), rssi:0
May 17 18:53:07 syslog: wlceventd_proc_event(527): eth1: Auth CC:C0:79:57:58:E9, status: Successful (0), rssi:0
May 17 18:53:07 syslog: wlceventd_proc_event(537): eth1: ReAssoc CC:C0:79:57:58:E9, status: Successful (0), rssi:0
May 17 18:53:10 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:53:19 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:53:34 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:53:34 dnsmasq[722]: script process exited with status 16
May 17 18:53:42 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:53:47 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:53:47 dnsmasq[722]: failed to allocate 100 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 100 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 100 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 100 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 100 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 100 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 103 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 103 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 105 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 108 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 117 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 118 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 138 bytes
May 17 18:53:47 dnsmasq[722]: failed to allocate 46 bytes
May 17 18:54:11 firewall: apply rules error(2857)
May 17 18:54:11 firewall: apply rules error(2892)
May 17 18:54:11 firewall: apply rules error(4580)
May 17 18:54:11 rc_service: waitting "restart_firewall" via watchdog ...
May 17 18:54:11 rc_service: watchdog 736:notify_rc restart_firewall
May 17 18:54:11 rc_service: watchdog 736:notify_rc restart_wan
May 17 18:54:11 services: apply rules error(17779)
May 17 18:54:11 watchdog: restart_firewall due DST time changed(1->0)
May 17 18:54:12 dnsmasq-dhcp[722]: failed to write /var/lib/misc/dnsmasq.leases: No space left on device (retry in 60s)
May 17 18:54:12 dnsmasq[722]: cannot read /tmp/resolv.dnsmasq: Cannot allocate memory
I don't actually know what is wrong yet or if the firmware update fixed anything. But strange that we both started seeing problems at similar times. Going back through the logs, this hasn't been a longstanding problems. This first appeared this morning at 9:41 am PST. I enabled ssh and logged in to poke around. After flashing I done see any space issues. I'll monitor it for a few days and see if this creeps up or if I have some kind of leak.
Code:
# df -h
Filesystem Size Used Available Use% Mounted on
rootfs 40.8M 40.8M 0 100% /
/dev/root 40.8M 40.8M 0 100% /
devtmpfs 124.8M 0 124.8M 0% /dev
tmpfs 124.9M 1.1M 123.8M 1% /tmp
/dev/mtdblock4 62.8M 2.2M 60.6M 3% /jffs