Yellow - Remote boot/restart

I have lost remote contact with my Yellow.
After an unsuccessfully attempt to update NodeRed today, the whole Yellow now hangs and has become inaccessible.
Is there a way to remote reboot/restart the Yellow?
Or is there som sort of watchdog built into it that automatically reboots the Yellow after a certain period of no response from the server?

You are best having a smart plug to remote power off and on again in this case that is not tied to the instance itself as a backup method to power cycle it when you need to.

And how would you manage to remotely control this smartplug? With a second HA instance on another Yellow, or some third party HUB just for that one plug?
Wouldn’t it me much easier if NabuCasa had designed in a HW watchdog onto the PCB? After all, it only takes a TTL flip-flop to make one.

Via VPN to the network in question using the app that it can be used with, this is one reason why I have my instance of HA in a virtual machine so it’s easier to manage it by just remoting into the host machine directly.

Well, most Add-On’s have an option switch named “Watchdog” which - if activated - will restart the Add-On if it crashes or becomes unresponsive.
What I want is a similar thing for HA itself.
That shouldn’t be rocket science (!)

As TH3xR34P3R suggests, I have my Yellow Box on a Kasa plug and, because the plug shows in the Kasa App of my Iphone, I can power cycle the Yellow Box wherever I may be.

I understand that this is an option, and that it will work - most of the time.
But if you’re not at home, and your ISP is down, you may - as I do - have a HA instance that controls heating, warm water and security. Then it’s nice to know that if HA crashes - for som reason - it will most likely come back up alive if a watchdog had been built right into the motherboard of the Yellow (or Green).
A smart plug isn’t going to be much use if your internet connection is down, but HA itself may function locally just as well, without internet connection - for a while.

You are right but I have that sorted out as well with the Comcast Storm Ready device. If the internet and/or power goes out, automatically the internet switches to wifi over cellular and it has a power backup of around 4 hours.

Yes, I know - so could my TP-Link router which had a SIM-Card slot. So Comcasts claim that they are the only supplier in North America with that solution, is B…S…
All routers with SIM support offers a fallback mechanism like that.
My problem is that my ISP (which has a monopoly in the region where I live), required that I only use their router when connecting to their network. So the TP-Link was obediently disconnected and put back in the closet. I couldn’t afford to run 3G only (besides, it was too slow).

You could connect your TP-Link router to the ISP router. With this you would have 2 wifi networks in your home and the TP-Link could be your main wifi. I would think that the TP-Link router (if it has a sim card option) would act like a Storm Ready and switch to the Sim card if & when no signal is coming in.
I have a Google Wifi router connected to my Comcast router and it is my main wifi at home. This does in fact contradict my earlier post in that my HA (and 99 % of my devices) are connected to the Google Wifi, and therefore my HA will not automatically go to cellular is signal is down. I would need to be home and manually switch to the Comcast wifi. The reason that my set up is like that is that the Google Wifi mesh network is better than the Comcast wifi (even with a pod).

If I managed to do all that you suggest, in the right order, and actually make it work, The skills needed would be far above the main crowd using Home Assistant.
Your advise may be technically correct and perhaps also work in reality, but it is definitely not a user friendly one as it requires technical skills far above the average!
My suggestion, however - requires absolutely no technical skills at all. If only the Nabu Dev Team had thought about doing it during the design phase of the Yellow (and Green), it would have given a valued and very important security feature, at no extra cost or effort, to all.

Sorry to have sound technical. I consider myself among the least technical in this forum, and there is so much that I don’t grasp.
You are right that my ‘plug’ solution would not work if the internet is down, but it for sure was useful yesterday when for an unknown reason some of devices (Zwave and Chromecast) became unavailable and a restart of HA did not resolve it. I did a power cycle, using the TP Link plug, and everything came back.
With regards to having two wifi routers ( A and B), it is really simple. The B router is plugged into the A router and it creates its own wifi. For A, the B router is just another device.
Not wanting to be more confusing, after posting my earlier comment, I actually tested my Comcast wifi at the other end of my home and realized that it has a better reach/speed than the Google Wifi. For now the Google Wifi is only used as a Guest wifi, which weirdly enough the Comcast router does not have.

I tried connecting two routers, one after the other, and the result was that everything stopped working, including my other computers and iPad’s, mobile phones etc, could no longer reach internet.
So I quickly gave up.
A few days later a techy friend came to visit and took a look, and could inform me about the following (of which I understood nothing) - I had to put the first router in “Bridge mode” in order to get this to work, he said. Then he discovered that both routers were transmitting WiFi in channel 11, consequently jamming each other to death. How was I to know?!?
So claiming that these things are easy, is BS.
End of discussion.

I’m sorry.