Unable to add thread devices | Home Assistant | Page 1

manic cliff Jan 3, 2026, 3:51 PM

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I bought a ZBT-2 which I configured as thread device. It correctly installed the OTBR addon. I followed the tutorial and added the credentials to my ios device.

When trying to add a new ikea remote, it just fails. Is there any way to debug this?

Steps I took on iOS:
Add device > matter device > new device > scan the code > it correctly detects it as a switch > click add to home assistant.

It then show 'This may take a few minutes' With a Connecting... spinner which eventually fails "Unable to add accessory" without further information.

The OTBR has a bunch of errors in the log but it's not clear how serious these are.

[NOTE]-BBA-----: BackboneAgent: Backbone Router becomes Primary!
00:00:34.027 [W] DuaManager----: Failed to perform next registration: NotFound
00:00:34.230 [W] P-RadioSpinel-: Error processing result: NoAddress
00:00:34.230 [W] P-RadioSpinel-: Error waiting response: NoAddress
00:00:38.662 [W] P-RadioSpinel-: Error processing result: NoAddress
00:00:38.662 [W] P-RadioSpinel-: Error waiting response: NoAddress
00:00:43.172 [N] MeshForwarder-: Failed to send IPv6 UDP msg, len:168, chksum:1edf, ecn:no, to:2ec3bb2f2a84d027, sec:yes, error:NoAck, prio:net, radio:all
00:00:43.172 [N] MeshForwarder-:     src:[fe80:0:0:0:8056:1064:e1d0:cbae]:19788
00:00:43.172 [N] MeshForwarder-:     dst:[fe80:0:0:0:2cc3:bb2f:2a84:d027]:19788
00:00:44.618 [W] SrpServer-----: Failed to handle DNS message: Drop
00:00:48.178 [W] SrpServer-----: Failed to handle DNS message: Drop
00:00:54.278 [W] SrpServer-----: Failed to handle DNS message: Drop

willow tulip Jan 3, 2026, 4:41 PM

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I copied this from a similar thread;
two QQ, can your phone see the network? https://play.google.com/store/apps/details?id=com.mdns_discovery.app is a usable app
(if not, that is the troubleshooting step)
Is the credentials really refreshed in the keychain?

users has reported that, more often than not, trying a new phone to do the pairing works well.
Worse god damn case - The IKEA devices support MQTT (Woh) https://www.reddit.com/r/homeassistant/comments/1pzvysh/new_ikea_matter_over_thread_devices_might/

mDNS Discovery - Apps on Google Play

Discovery tool for browsing and resolving locally registered services.

From the homeassistant community on Reddit: New IKEA Matter over Th...

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manic cliff Jan 3, 2026, 5:30 PM

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After a few hours of cursing, I managed to pair the devices. I'm not sure which one of 2 changes was responsible:

I forced some IPv6 settings on my unifi router
I set an internal HA server ip in the HA iOS app

vocal steeple Jan 3, 2026, 8:57 PM

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manic cliff After a few hours of cursing, I managed to pair the devices. I'm not sure which ...

Can you share what Unifi IPv6 setting you changed? I think I’m struggling to get my Eve Matter device to add to HA even though I can add it to iOS Home.

manic cliff Jan 4, 2026, 11:17 AM

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My ISP doesn't support ipv6, so I enabled it for my (default) network with the static option and entered fd00::64

stuck cliff Jan 7, 2026, 5:08 PM

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yeah, unifi equipment is a common source of problems for people using matter. It's very important that your phone and home assistant and your thread border router all be on the same network link (vlan) and also that multicast packets - for both mDNS and ipv6 router announcements - can be sent between them.

#Unable to add thread devices