N300A IP reboots

[#1]

I have a Cudy WR3000s running OpenWrt. When I look at the System log I see that every night between about 00:00 and 04:00 lan1 link goes down then up again over a period of about 18 or 20 seconds. The only thing connected to lan1 is my N300A IP VOIP base station. If I manually reboot the N300, the system log shows the same sequence of messages in about the same time, so it looks as though the N300 is doing a reboot every night. Looking at the N300 interface there don’t seem to be any settings that may control this.

Whilst losing my telephone connection for about 20 seconds every night when I’m asleep is not a great concern, I’m interested to know whether anybody else has noticed similar behaviour. Is this normal for the N300A IP or do I have a problem?

[#2]

I have a WR3000H.  running Openwrt as a bridged AP. with an N300 connected to lan2. Not noticed it before but just checked the log and mine does the same. 

[#3]

I used to have N300 but now have N510ipPRO which is actually very similar.

That seems to do a time sync every night shortly after midnight, maybe the N300 is doing something similar and that creates the symptoms you see?

[#4]

According to the router log, the actual link is dropping. its then reconnecting some seconds later and getting its IP. 

The N300 uptime on its status page shows 25.01.2026 00:51 , so it does look like a reboot as @IMM says

Sun Jan 25 00:51:43 2026 kern.info kernel: [210351.786229] mt7530-mdio mdio-bus:1f lan2: Link is Down
Sun Jan 25 00:51:43 2026 kern.info kernel: [210351.791505] br-lan: port 2(lan2) entered disabled state
Sun Jan 25 00:51:43 2026 daemon.notice netifd: Network device 'lan2' link is down
Sun Jan 25 00:51:56 2026 kern.info kernel: [210364.526923] mt7530-mdio mdio-bus:1f lan2: Link is Up - 100Mbps/Full - flow control off
Sun Jan 25 00:51:56 2026 kern.info kernel: [210364.526949] br-lan: port 2(lan2) entered blocking state
Sun Jan 25 00:51:56 2026 kern.info kernel: [210364.540237] br-lan: port 2(lan2) entered forwarding state
Sun Jan 25 00:51:56 2026 daemon.notice netifd: Network device 'lan2' link is up
Sun Jan 25 00:51:56 2026 daemon.info dnsmasq-dhcp[1]: DHCPREQUEST(br-lan) 192.168.5.71 xx:xx:xx:xx:xx:xx
Sun Jan 25 00:51:56 2026 daemon.info dnsmasq-dhcp[1]: DHCPACK(br-lan) 192.168.5.71 xx:xx:xx:xx:xx:xx N300

I've just tried disabling the Automatic firmware update, lets see if it still reboots tomorrow morning ?

[#5]

Interesting, my N510 shows a time sync at 02:11 this morning but has been "up" since 17:57 yesterday. I'll look again after 6pm today.

[#6]

@MisterW , @HPsauce Thanks for checking your systems. It looks as though the daily reboot is normal for the N300A IP and not anything I need to worry about.

[#7]

My N300-IP is presently showing "Uptime since 25.01.2026 00:35"

A Google search found this old TBB thread discussing the reboots and mentions a firmware bug, but in an older firmware version (which may still not have been corrected?).

Quote:  "AFAIK there has been a bug in the firmware for some time. You'll probably see the uptime change to the current time every 18h 12m 15s which equals 65535 seconds, the max size of a 32-bit short integer. I guess someone defined the variable incorrectly in one of the updates."

[#8]

For info my N300 is running firmware 42.262 , I wouldnt have thought its been updated for some years now ?

The time between reboots seems definitely to be > 18h , its close to 24hr although from the log below it does seem to be getting earlier ? Mines only been on for a few days since it would have been powered off whilst on holiday

Fri Jan 23 01:20:06 2026 daemon.notice netifd: Network device 'lan2' link is down
Fri Jan 23 01:20:06 2026 kern.info kernel: [39297.069707] br-lan: port 2(lan2) entered disabled state
Fri Jan 23 01:20:06 2026 kern.info kernel: [39297.069819] mt7530-mdio mdio-bus:1f lan2: Link is Down
Fri Jan 23 01:20:19 2026 kern.info kernel: [39309.679907] mt7530-mdio mdio-bus:1f lan2: Link is Up - 100Mbps/Full - flow control off
Fri Jan 23 01:20:19 2026 kern.info kernel: [39309.679932] br-lan: port 2(lan2) entered blocking state
Fri Jan 23 01:20:19 2026 kern.info kernel: [39309.693049] br-lan: port 2(lan2) entered forwarding state
Fri Jan 23 01:20:19 2026 daemon.notice netifd: Network device 'lan2' link is up
Sat Jan 24 01:06:30 2026 daemon.notice netifd: Network device 'lan2' link is down
Sat Jan 24 01:06:30 2026 kern.info kernel: [124859.423539] br-lan: port 2(lan2) entered disabled state
Sat Jan 24 01:06:30 2026 kern.info kernel: [124859.423647] mt7530-mdio mdio-bus:1f lan2: Link is Down
Sat Jan 24 01:06:42 2026 kern.info kernel: [124871.912573] mt7530-mdio mdio-bus:1f lan2: Link is Up - 100Mbps/Full - flow control off
Sat Jan 24 01:06:42 2026 kern.info kernel: [124871.912600] br-lan: port 2(lan2) entered blocking state
Sat Jan 24 01:06:42 2026 daemon.notice netifd: Network device 'lan2' link is up
Sat Jan 24 01:06:42 2026 kern.info kernel: [124871.925890] br-lan: port 2(lan2) entered forwarding state
Sun Jan 25 00:51:43 2026 kern.info kernel: [210351.786229] mt7530-mdio mdio-bus:1f lan2: Link is Down
Sun Jan 25 00:51:43 2026 kern.info kernel: [210351.791505] br-lan: port 2(lan2) entered disabled state
Sun Jan 25 00:51:43 2026 daemon.notice netifd: Network device 'lan2' link is down
Sun Jan 25 00:51:56 2026 kern.info kernel: [210364.526923] mt7530-mdio mdio-bus:1f lan2: Link is Up - 100Mbps/Full - flow control off
Sun Jan 25 00:51:56 2026 kern.info kernel: [210364.526949] br-lan: port 2(lan2) entered blocking state
Sun Jan 25 00:51:56 2026 kern.info kernel: [210364.540237] br-lan: port 2(lan2) entered forwarding state
Sun Jan 25 00:51:56 2026 daemon.notice netifd: Network device 'lan2' link is up

[#9]

After a time sync at 02:11 this morning my N510 shows up since 12:10 (midday) today which is roughly 18 hours 13 minutes from the previous time.

As @RobPN found: Quote:  "AFAIK there has been a bug in the firmware for some time. You'll probably see the uptime change to the current time every 18h 12m 15s which equals 65535 seconds, the max size of a 32-bit short integer. I guess someone defined the variable incorrectly in one of the updates."

So the bug isn't just in N300A. 😂

.

[#10]

I just waited to see if mine 'rebooted' at 18h 12m, and sure enough it was bang on time!

Now showing "Uptime since:25.01.2026 18:47"

[#11]

Interestingly just checked and mine now showing uptime since 19:04 which is 18h 12m after the early morning reboot !

However, there's no evidence of a reboot in the router log. So it would seem the 'bug' is just causing a reset in the calculation of 'uptime'