Hub 2 router constantly restarts

[#1]

Could it be this 'hardware' problem if you discover your Hub Two remains stable with no LAN devices connected?

https://community.bt.com/t5/BT-Devices/BT-Smarthub-2-reboots-once-a-day/m-p/2205344#M25782 

Yes, it is possible for traffic passing through a router to cause it to misbehave.  It would be due to a bug in the router's firmware though.  A lot of routers have a watchdog timer.  When an unresolvable 'software' error occurs, and the watchdog timer is not reset, it will cause the router to reboot to try and recover from the fault.

[#2]

Thanks for the link.

In my situation I have a switch and I don’t see the LAN ports disconnecting. In fact I have a brand new switch although I’ve tried the old one and I get the same reboot. It makes me wonder whether a device on my network is doing something rogue.

Since I disconnected all LAN ports on the router, it’s stayed on - 55 mins, the longest today.

[#3]

How is the switch powered ? What make/model is it ?

[#4]

https://www.amazon.co.uk/gp/product/B07J652QS3/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

has its own power adapter

i could try the old one again - I only replaced it because I need more ports

[#5]

I'd suggest if possible, leaving it with no switch connected for say 24 hrs to see if that stops the reboots.

If it does , then try the old switch first and see if that causes reboots.

Let us know the results.

[#6]

I’ll try that. Thank you for all your input. Everyone has been very helpful.

I’ll update tomorrow PM.

My connection remains open after 1.5hrs which is good news.

[#7]

In principal, using a switch should be fine.

FWIW, one part of my network is configured like this: -

LAN1 > 5 port unmanaged switch > 8 port unmanaged switch > 7 wired clients
                               > 5 port managed switch > 2 wired clients

And I've never seen a restart with a Hub Two on the line.

Critical question here is to ask exactly how your network is configured, what devices you have in your house and how each is connected? Any powerlines or additional access points in play? I agree that it could be a rogue device triggering the behaviour and I'm keen to get to the bottom of it.

In the meantime, I'll see if I can grab anything remotely that offers any clues. Most of the log extracts you have provided are from after the event, rather than before it. No need to provide any more as I should be able to grab them from here.

[#8]

That’s great. Thanks Bob.

All LAN ports and switch are now disconnected and the router is working fine on wireless (3.5 hrs now).

I currently have 8 CAT5 cables to different rooms connected to both the router and the switch (more to be added in time).

These supply the following;

3 x TVs

5 x non-modem routers (acting as local Wi-Fi & extra LAN ports).

I assume the TVs are fairly benign but the non-modem routers are cable connected to 3 windows computers, 1 laptop, 1 XBox plus various wireless gadgets. The windows computers are run by my kids and I have no jurisdiction over their use.

There are no powerline devices.

This setup has been in place for 2 or 3 years and worked just fine. Problems started earlier in the year - constant dropouts. In haste I changed the modem (quick Amazon purchase) but problems persisted so I changed the switch. The problems continued. I managed to get a new Hub2 from Plusnet but found it was constantly powering down as I’ve described. 

[#9]

I will reconnect everything later - room by room, to see which connection affects the router.

Thanks.

[#10]

---

@mrben wrote:

5 x non-modem routers (acting as local Wi-Fi & extra LAN ports).

---

You have 5 other routers on the network!?

What make/model are these and how are they configured? i.e. have you repurposed old kit by assigning an IP outside of the Hub Two allocation and disabling DHCP, or are they devices that have a dedicated access point or repeater mode within their firmware?

I've grabbed the logs now so will have a look through when I get a moment.

In the meantime, I have taken the liberty to push the latest firmware to your hub (currently in the process of being deployed). That way we can avoid chasing our tails with an issue that may have been resolved in the most recent build.

You'll need to power your hub off/back on again to apply the update.

Edit: right, have had a cursory glance at the logs and one thing that definitely stands out to me is the fact that there's what looks like an Apple Airport Extreme device utterly spamming the Hub Two with DHCP requests, e.g: -

11:43:17, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:16, 13 Apr. Receive a DHCP request
11:43:13, 13 Apr. Receive a DHCP request
11:43:13, 13 Apr. Receive a DHCP request
11:43:12, 13 Apr. Receive a DHCP request
11:43:12, 13 Apr. Receive a DHCP request
11:43:12, 13 Apr. Receive a DHCP request
11:43:12, 13 Apr. Receive a DHCP request
11:43:12, 13 Apr. Receive a DHCP request
11:43:12, 13 Apr. Receive a DHCP request
11:43:12, 13 Apr. Receive a DHCP request

 You might want to isolate this device for investigation first? 🤔

[#11]

I’ll have a look at that first.

I have 2 airport extremes - both installed years ago. Now defunct of course.

The kids have one of these each. To be fair they went in at about the same time as the problems started but I think I put them in in response to constant Wi-Fi dropouts. I haven’t configured them beyond the state they came out of the box.

https://www.amazon.co.uk/gp/product/B001FWYGJS/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

[#12 · Accepted solution]

I think it's the one with the MAC address ending 43:06 that's misbehaving.

I don't have much experience with Airports but perhaps try resetting/reconfiguring from scratch.

You definitely do not want it acting as a second DHCP server on the network as that would play havoc (same goes for all of your access points).

[#13]

Thank you Bob and to everyone else who’s contributed.

The offending Airport Extreme has been removed and all now seems well in this household. I’d like to think this is the problem resolved.

I can’t thank you enough for helping me out. I’m not an IT person and in this busy world it’s hard to find time to deal with these kind of problems and frustrating when everyone in the house comes to me to complain about their access. It’s been going on for about 3 months so I’m hoping I’ll get some peace at last. I was cursing the Hub2 but it actually did me a favour.

Cheers guys!

[#14]

@bobpullen 

Accepting that there was a device misbehaving on the network...

1. Should the Hub Two be more resilient to such "abuse"?
2. Accepting that it is not, should the reason for the restart have been different to the "power switch press" reason stated in the logs?
3. Has this experience been added to any knowledge base?
4. Has the issue been forwarded for rectification in a future firmware release?

I think I recall other Apple devices behaving in this manner (repeated DHCP requests) during the trials but such did not bring about any restarts.