Device failed to pair after 'Setting Up'

Configuration Matter/Thread
1

I’ve attempted to pair a handful (pack of three) of Ikea BILRESA and cannot seem to figure out why it keeps failing to pair at “Setting Up”.

It’s notable that I have 2 Matter over Wifi devices (GE Cync) setup without any issues at all.

Versions:

  • Core - 2026.3.4
  • Supervisor - 2026.03.2
  • Operating System - 17.0
  • Frontend - 20260107.2
  • Matter Server - 8.3.0
  • OpenThread Border Router - 2.16.5

I run a fairly vanilla HAOS on an incus vm with a ZBT-2 connected via USB with a 2.0 extension cable to avoid any potential interference. IPv6 Is configured automatically by incus, I believe via SLAAC. The VM gets a global and link-local address and HA is configured with “Automatic”. The bridge interface is configured with accept_ra = 2 and forwarding = 1, but the actual running vm interface, from what I can tell, has accept_ra = 0 (this is an area I’m out of my depth).

Previously I was trying to add my thread devices using an slzb-mr3 with dual radios, but could only ever get Zigbee to work which is why I switched to the zbt-2.

Every time I try to pair the device(s) by scanning the QR code It goes from “Connecting” to “Setting Up” and eventually fails with a generic pairing failed. While running the pairing I ran avahi-browse -r _matterc._udp and I see devices pop up with a prefix that doesn’t match anything known.

I turned on debug logging and I see for the same IP as what I get out of the mDNS query:

  • srp adds registration for the child associated with that IP
  • high volume of “Rx data poll” logs for the child
  • Frame rx failed, error:Duplicated error
  • eventually srp deletes service matching the initial registration

Most of the debugging steps I’ve read suggests either turning on ipv6 at the local network router, which I can probably do, but I’m not convinced should be necessary because, as I understand it, the thread network should be independent. I’m hoping I could get some help figuring out what I’ve misconfigured or why I might need to enable ipv6 on my local network to get this to work.

2

Rest assured it is necessary. Onboarding involves ‘phoning home’ via IPv6. Yes, a one-off, after which you can stay entirely local.

1 Like
3

As mentioned above, the Thread wilreless standard uses IPV6 for network transport. No IPV6, no Thread conversations between HA and devices.

4

IPv6 and Matter: The key to forcing the entire world into IPv6, something that everybody has been postponing for decades.

It isn’t just desired, it is mandatory in the Matter standard.

5

I didn’t mention in the OP, but I also don’t see any commissioning errors (or anything related to the device I’m trying to pair) on the matter server. I just see logs in the openthread border router. If this were part of the “phone home” process, would that not be part of the matter commissioning process and I’d see some errors there?