A year ago, I had a C-7 and a C-4 hub. The C-4 managed two categories of devices:
Network-based devices, particularly those that required polling, to keep the load off the primary hub
Zigbee devices that in some manner don't play nice with the rest; a light that's a poor repeater and some very chatty mmWave motion sensors
I purchased a C-8 a while back, and did the migration backup etc. from the C-7 to the C-8. I understood at the time that the C-8 would adopt the network identity of the C-7, so if I ever reused the C-7, it should be on a different channel. No worries.
The C-4 has been showing its age in a couple of ways, so rather than continuing to hope Hub Protect will gift me a free extra hub, I just rolled it over to the idle C-7. But now, both Zigbee networks have the same PAN ID. They're on separate channels, though, so I wasn't expecting any problems.
However, I just noticed in the Zigbee network graph that I'm seeing this:
When I hover on the Unknown devices, they have the Addresses of devices that are theoretically paired to the other hub. I haven't yet seen any problems with them, but there hasn't necessarily been time for them to crop up.
Have I shot myself in the foot here or is this primarily a UI issue? Is there a way out that doesn't involve re-pairing all devices on the primary hub to a new PAN ID?
The radios are going to share an IEEE address (no changing that on a C-4 ... well, actually, with that model you might be able to take the HUSBZB-1 stick and use third-party software to flash a new one, but I don't have any experience trying that, nor have I seen anyone here do it). But that shouldn't be a problem as long as they have different PAN IDs and are on a different Zigbee channel.
So, it sounds like you just need a new PAN ID. A Zigbee radio reset can do that. If you're on 2.3.7, the easiest way to do that is probably to temporarily downgrade to 2.3.6 using the Diagnostic Tool, reset the radio from Settings > Zigbee Details, then re-upgrade (this will probably change in the future).
Resetting this on the old hub should not affect the new one.
Fortunately, the C-4 is probably just going to the great junkyard in the sky, but it sounds like the C-7 needs the new ID. I've already noticed that it doesn't have a Zigbee reset option in 2.3.7.
2.3.6 isn't an option, but several iterations of 2.3.5 are in the list of old versions I can drop back to. That enabled a reset, and it appears I do indeed have a new PAN ID. Now I just have to re-pair the four things on that hub again.
But the downgrade seems to have gotten me there for the time being.
I'm guessing that what happened is all the devices paired to the C-8 thought there had been a channel switch and were hopping over to the C-7, which had no idea who they were.
That won't work if you don't want to re-pair all devices. That's part of how the migration magic works. If you ever reset the migrated-to Zigbee radio, it will return to the factory IEEE instead of the migrated IEEE (and get a new, random PAN ID). But, again, that's not something you want to do in your case.
I might not be grasping what you're showing as a problem. The "Unknown" devices must have existed in your old network, didn't have an associated device there, and still don't on your new one (not surprising given that a migration takes things as-is). The best idea would be to reset those devices, or just un-power them, etc. Of course, that depends on you being able to figure out what they are... Otherwise, there shouldn't really be any harm (unless maybe they are things like an old smart bulb that's repeating and probably shouldn't be).
@bertabcd1234 I think he already fixed the issue by resetting the C7 Zigbee radio.
Just FYI there is an endpoint you can use to download the last hotfix update from each major version, but obviously 2.3.5 worked as well so you don't need it now
That is not available yet, but it will be in the future once they add it.
Yep, the reset and re-pair of the 4 devices on the C-4/7 seems to have fixed it. I have Z-wave disabled on the C-7, but would I expect any similar issue there?
If you have not reset the Z-Wave radio since migrating you will need to do that if you want to use it. That will create a new network ID and clear out all the old devices from the radio database. When you migrate a cloud backup the network ID is copied over to the new hub.
I migrated from the C-7 to the C-8, meaning the C-8 now has the same PAN ID and IEEE address as the C-7
There is a large (~40) set of devices associated to the C-8
I migrated from the C-4 to the C-7, which doesn't change the C-7's PAN ID or IEEE address
The end result is that the same IEEE address and PAN ID were broadcasting on different channels. Some of my devices thought there had been a channel change and were trying to talk to the C-7 on its channel, which had no idea what they were. Meanwhile, the C-8 was sending them commands on its channel that they weren't listening to.
The solution was a reset because that generates a new PAN ID. All the confused devices saw another "channel switch" back to the C-8's channel and started working again. No need to re-pair anything on the C-8.
You're correct that I needed to re-pair the devices that actually were supposed to talk to the C-7, but that's only four of them and three of them are very simple to re-pair.
Okay, I'll probably just wait. There's currently no need to use Z-Wave on that hub, I just don't want to disrupt my current network by accident if future-me turns it on at some point and doesn't remember this discussion.
Hey, I noticed on the latest build that my C-8 now has radio reset options on the diagnostics page. So I updated the C-7 and went to the same place on the C-7 and... didn't find it.
Is a similar option coming to C-7 shortly, or is there a different reason it's not showing up?
What version is your Diag Tool on your C7 hub? My C7 Diag Tool is running 1.1.125. I have not tried updating it today. I see the new Advanced options at the bottom of the tool, which includes the radio reset options.
I just ran the manual update and my C7 Diag Tool is now running v1.1.126. This hub is probably part of the Diag Tool Beta program, though... So, YMMV of course.
If you ever reset the migrated-to Zigbee radio, it will return to the factory IEEE instead of the migrated IEEE (and get a new, random PAN ID). But, again, that's not something you want to do in your case.
