Trouble adding first matter device. Error: Network is unreachable

Hi @kevort, I actually found a fix. The issue stems from limited IPv6 support in Synology DSM. The solution is twofold:

  • Fix Routing: Run a script on your Synology NAS to manually add the missing IPv6 routes.
  • Docker Config: Ensure IPv6 is enabled for your Docker network.

Important Prerequisite: Your OTBR (OpenThread Border Router) must be on the same network as your Home Assistant instance.

You can find the full details and script references here: