All connections lost after Hub system restart reason: SAAF

[Daveiw100]

I have BT full fibre, which has been pvery stable for several months.

This week, I lost connection to all devices connected to the hub, and could not access any device remotely or via the LAN.

The hub appeared to be powered up OK (normal blue light status). The fiber connection box had the normal green LED's.

I manually re-booted the hub (power off/on), which restored connections to all devices.

Technical log showed  'system restart reason: SAAF' at the time that connections were lost, then no further entries in the log until I performed the power off/on reset.

I have seen posts in this forum to the effect that a system restart occurs at regular intervals, but my questions are:

What causes the System Restart?

Why did the hub not successfully restart?

How can I disable this regular System Restart?

How can I ensure that the hub sucessfully completes the System Restart?

[Les-Gibson]

The SH2 occasionally fails to restart correctly following an update but it's no big deal, see the following link for instructions on performing a factory reset. If that doesn't sort it then you may have a faulty hub.

SH2 Factory Reset 

[Daveiw100]

Hi, thanks for the reply.

With respect, this is a big deal.  I was on holiday and unable to access any of my home devices for several days - cctv, alarm, heating etc.

I just want to ensure this does not happen again.

If I cannot access the hub remotely, it is not possible to perform a factory reset. Also a factory reset would require entering all configuration settings again, or a restore from backup

[Keith_Beddoe]

I think you can do a remote restart from the BT App, as this has been mentioned before.

Can I reboot my BT router remotely?

The My BT app is the quickest and easiest way to get help when you need it, and you can manually update the router from your smartphone. The app also lets you restart your BT Hub remotely and track any faults you have raised.

https://www.bt.com/about-my-bt-app

This may only work with the latest smart hub 2, but you would have to try it.

I would expect it uses the same method that the helpdesk use, to remote restart your home hub. Because the BT app is only used by the account holder, you could not reboot another persons home hub.

[Daveiw100]

Keith, thanks for this info.
I was not aware that a remote reboot was possible.
I will certainly check this out

[imjolly]

@Daveiw100 

the regular system restart which you see posted previously affected some customer but only on ADSL and FTTC not like you on FTTP

A system restart could be triggered by power cut, firmware update or just a system fault.  occasionally the hub does not restart correctly after a firmware update and need customer to manually restart.  as I said with FTTP you don't get the   regular restarts which are posted by customers on adsl/FTTC

you cannot ensure hub restarts successfully but hopefully @Keith_Beddoe  suggestion using MYBT app will work 

[Keith_Beddoe]

It would be interesting to know if it works, for the benefit of other forum members. The information was taken from an earlier post.

To be 100% sure, you would have to connect your phone to mobile data.

Provided the hub is still online, and connected to the BT management system, then I would expect it to still work.

[Les-Gibson]

You should have mentioned that you were away from home in your first post, it can make a big difference.

Your hub will have a dynamic public IP address that by definition will change occasionally.

The only way to maintain a constant connection to your hub whilst you are away is by using DDNS which some providers (e.g. No-IP) will provide on a no fee basis but you will be required to confirm that you still need it every 30 days. Alternatively, you can pay a small fee and not have to confirm every month

[Daveiw100]

@Les-Gibson  - Sorry I did not make that clear in my original post.  I have several connected devices to the home network which I regularly access remotely (CCTV, alarm, NAS etc). I suddenly was unable to connect to any of these when I was on holiday.

When I returned from holiday, I was still unable to access any connected device via the Local Area Network, even though the router was powered up and usual blue light appeared to indicate good status.

@Keith_Beddoe  – I have successfully tested a remote router reboot from the MyBT app. Router log shows “System Restart Reason TR69”. 

I’m not sure if this would have been successful in my original issue when the router was powered up with good blue light status, but had failed to restart.

BTW it is not possible to perform a remote restart from the MyBT website, it is only possible from the MyBT app.

@imjolly – I am on Full Fibre FTTP, and router restarts (Reason SAAF) are occurring at regular intervals, approximately every 2 weeks.

I have read somewhere that these should only occur “out of hours”, but logs show various timings, examples 00:22, 17:02, 18:12, 20:18, 10:41, 02:29

[imjolly]

It was down to the DLM causing the regular restarts on ADSL/FTTC but  DLM not involved to same in FTTP  Have you looked to other causes more internal

The 14 day reset could occur at anytime.  I had it happening and found if I reset my Hub about 12.30/1am then resets happened when I was not using internet.  the system always came back up after couple of minutes and did not cause any problems.  This was all on FTTC then the resets just stopped all of a sudden.