Hot Spare/Ethernet Repeater

I have an idea here and feel free to shoot it down if you want.

So right now the hub is your single point of failure in the network as it is the only way to communicate to the outside world. If you could make an easy way to use 2 hubs together where one is the primary and one is secondary they could sync over wired Ethernet to talk to each other and back each other up. This would be in case one goes down the other would be there ready to take over.

So I broke my hub messing around with it and trying that external antenna thing. I did it and knew full well when I started I could totally kill my device. That said when I broke the hub it still kind of worked but not all the way. I bought another and actually 2 of them because I saw how important this hub is to the network. If it is dead everything I have setup is not going to work.

So I have an extra hub sitting in a box just in case something ever goes wrong with my current hub I can use the cloud feature to move the entire z-wave network over to the new hub. It is my cold spare.

Now if I could take advantage of this spare all the time and just have it run and be ready that would be ideal. This is the idea...

Make it so you can have a hot spare on the network that would automatically take over if the primary goes offline. Also while it is sitting there make it so that device is either a repeater tied back to the primary hub using Ethernet or just make it join the mesh as a plugged in repeater. Then if the primary hub ever fails the secondary is already online and tied in with the cloud so it is ready to take over.

Now how hard or often you could migrate the z-wave network between controllers or if you could host the network jointly on both controllers as merged? Or wait an appropriate amount of outage time like 1-2 hours before migrating? Or prompt the user to migrate so they can determine it is really dead?

This would not only increase your hardware sales but also your cloud sales as you would need all of that for it to function. Just an idea for those of us who like to have redundancy in our networks.

They aren't designed to do that and then you have the radios to deal with. a z-wave or zigbee device can't share multiple radios. When paired they are locked to that hub. Now what the cloud back will do is restore the radio settings to the new hub and set the id of the hub to match the old hub so the existing devices connect to it. There is no real way to do automatic failover though. Zigbee is easier as the database is stored in the config but you still have to include them to the new hub but they will slot into their old place

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Not to mention the joy of getting all the Zigbee devices to pair again. Yes, hubitat puts them in the correct slots for Rule machine but you still have to visit each device and convince it to re-pair.

Sadly no way around that

That is why I am just saying if they could build it to do that...

Or if there is a way to sort of "clone the MAC address" or something like that? make it like a local cloud node? I guess the zigbee part I don't know enough about as everything I have is z-wave and when I did a hub migration it seamlessly handed everything over to the new hub with the cloud move.

Again with the zigbee specs alone, that wouldn't be feasable. They would have to rebuild the zigbee specs from scratch

Like if one vendor owns all the "nodes" there should be some way to separate the main node from the hub either virtually or physically. So if the hub died you could swap the radio into a new unit. But also if that radio died to be able to do the same thing. To make it more of a robust fail proof solution where it could just become the device it is replacing.

I don't know enough about zigbee but if it is pairing to that radio and hub couldn't there be a way to take that key that it paired with and copy it over and clone the entire thing to a new device?

It's only going to work if Zigbee and Zwave stacks were designed (the protocols) to have hot backups. High availability and home automation don't fit in the same market segment.

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I don't think that is possible given current zigbee architecture. As to z-wave, ever identifier is different by design... One of the reasons it's a pain to work with. What you're asking isn't a software limitation, it's a hardware limitation overall.

I picture it more like SSH copy/clone, it is an authenticated paired and unique key but if one vendor has access to the entire thing and control of the entire radio stack couldn't they mirror it?

It doesn't need to be like hot hot on air at the same time, just like notify hey this hub is down do you want to roll over. Then the hub that is already on air and could be already loaded up gets the cloned database and keys. Then it would take over.

Or if it becomes easy to move it could down its radio interfaces and the keys and devices were already loaded on the other one and it just turns up its radio.

So as you add a device to one hub it adds to both hubs but one hub has the radios turned off and you can't access that hub directly it is "sleeping" so to say. The radio identifiers and all that are identical in every way, the addresses and keys are cloned from the first unit. So unit 1 goes offline, unit 2 turns up its radios and unit 1 gets the command if it ever comes back to go radio down.

I'm gonna let @mike.maxwell or @bcopeland field this

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LOL I like your statement that high availability and home automation aren't in the same market segment. I feel like they could be, like look at Apple Homekit, they have one hub as active and the others are on standby if you have more than one Apple TV on your network.

Sort of taking that approach with the Hubitat but it gets way more complex since the radios are involved...

No I appreciate your feedback I don't know much about this stuff from protocol side, you seem to know way more than I do. I just am trying to think of it from a different angle and ask why not? Not trying to challenge you on it as you are probably right.

There is mesh routing and device IDs to deal with. Having two controllers with the same ID for a few seconds could be a bigger problem than a network outage.

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Not to mention the security issues involved.

I can see what the OP is saying. For zigbee If you could go to the spare and put in the Pan ID and Extended Pan ID of the 'worker' wouldn't that just take control of the zigbee devices.
For z-wave............. :man_shrugging:

Don't know enough about all this radio malarkey to give any sort of informed decision.

I don't think it's that simple because zigbee uses aes128 encryption

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