So, after the recent storm in the UK, I was without my FTTP connection for about 72hrs.
This was my first time with Hubitat and no internet connection and I thought that I'd share my experience, as having local execution was a key requirement.
1/ This maybe a BT Smart Hub 2 (Router) issue but I couldn't access my hub by either wifi or ethernet:
2/ At the same time as trees falling across my fibre connection - in three locations, I also experienced a power cut for 6hrs. When the HE powered back on, the clock started from midday (I think!), this meant that all my time based triggers fired at the wrong time of day. And because of issue #1, I wasn't able to reset the time during the period my internet connection was down;
3/ I use Hue lights controlled via HE and over time my lights (Mainly light strips) lost their scenes and reverted to bright white. I wasn't able to use the Phillips Hue app to set scenes and, I assume, that due to no connection to the Hue cloud lost the last used scene;
4/ I use wi-fi lights externally as the range is better and control these via Alexa with virtual devices. Obviously without any internet connection, I lost my control of these devices - as expected;
The combination of these issues meant that my smart home became very dumb very quickly and I had to resort to turning devices on with physical switches! In all seriousness, the fact that HE operated locally meant that some automation still occurred but the safety net of HE not requiring the cloud was lost due to the issues above.
As a result, I have now created HE Scenes for all of my Hue lighting scenes to solve issue #3 but was very surprised that my router stopped issuing IP addresses or allowing wi-fi access when my internet connection was lost.
Has anyone else had experience of running HE without internet connectivity and found a way of addressing these issues?
My experience has been I can access the hub just fine without an internet connection, but I have not had that happen at the same time as a power failure. It seems like if you could address this issue HE would have worked as expected, though you probably would have had to manually reset the time via the UI. I'm guessing (but don't know for sure) the issue there is HE uses a software clock rather than a hardware clock and relies upon a periodic time sync to adjust for drift. I've read in other threads (see below) that if the hub loses power when it comes back online and can't do a time sync from an NTP server it just resumes where it left off, which would make sense with my software clock theory. Sounds like what happened in your case.
Not familiar with the BT (British Telecom??) router but the fact that it stopped working entirely without an internet connection seems less than optimal. A UPS on your HE would probably help quite a bit. It might not keep the whole thing running for 6 hours but it might! Especially if the UPS has a 5v dc output.
Yeah we call them ONTs here but same concept. Still, even with the internet connectipn unavailable the router should work just fine while it has UPS power.
Agreed, I need to look into this more. FYI - I use Raspberry Pi's for Influx logging and they also stopped working as they couldn't obtain an IP address from router DHCP allocation.
You could always bring up an NTP server on one of those and redirect HE to it... that would address your time issue as well (assuming your router works). If you wanted to get REALLY fancy you could use a GPS as a time source but that seems overkill.
another thought - If it is an issue that the router didn't give the hub an IP address (due to power recovery sequencing or other}, you could always assign it a static IP address to the hub. That is supported now in the hub interface ui.
In any case, your DHCP server needs to be the most reliable piece of your network puzzle. Because without it bad things happen on power recoveries.
Good point. Maybe it was just a timing issue. @UKMedia did you take any steps to try to re-establish connectivity to the hub or did it just reappear at some point?
I powered down the router and Hub and then powered the router back on and then the hub. I have reserved an IP address in the router rather than assigning a static IP Address, not sure if that made a difference?
FYI - I've raised this issue within the BT Forum and have been advised to factory reset the hub as it should support wi-fi and DHCP allocation without an internet connection.
Ah ok. I can see having an issue once power failed and was restored (perhaps the sequencing issue @JasonJoel references) but for it to just suddenly drop devices because the WAN connection disconnects sounds weird.
I ended up tossing all my telco-provided gear (except for the ONT) and all my consumer-grade network gear and going Unifi all the way. Works a lot better,
Yep, that's the approach I want to take but having just managed to persuaded my wife that I need a Samsung 49inch monitor and a new Nvidia 3070 graphics card, I may delay the replacement of the free router!
