Network problems for setup with Secondary Router

Hi, I installed Home Assistant Operating System on a NUC. NUC is connected to a secondary dedicated router(switch) that is only used for my home automation devices.

Everything works fine, but I can not install Add-on in HA. I think must be some network configuration issue in my routers.

If I try to install any Add-on, I get error in log:

21-08-03 10:52:51 INFO (SyncWorker_4) [supervisor.docker.interface] Downloading docker image homeassistant/amd64-addon-mosquitto with tag 6.0.1.
21-08-03 10:53:06 ERROR (SyncWorker_4) [supervisor.docker.interface] Can't install homeassistant/amd64-addon-mosquitto:6.0.1: 500 Server Error for http+docker://localhost/v1.41/images/create?tag=6.0.1&fromImage=homeassistant%2Famd64-addon-mosquitto: Internal Server Error ("Get "": net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)")

Internet access on HA seems to work. Could update HA from 6.1 to 6.2. Also, the weather for example updates, meaning HA is connecting to external weather server.

Main Router Configuration(LAN 10.1.0.x):

  • Static Routes for to be handled by gateway Router)
  • Port Forwarding configured for 8123 to

Secondary HA Router Configuration(WAN, LAN 10.10.0.x):

  • DHCP Enabled
  • WAN IP = seen on main network)
  • Router LAN IP =
  • Configure NUC to have IP (via DHCP Reservation)
  • Port Forwarding configured for 8123 to (to NUC)

What are the DNS settings in Home Assistant?

Hi, not sure where to find them. Will google it and get back to you.

In the supervisor / system panel. Click the “CHANGE” link next to your IP address in the Host box.

I clicked on the “CHANGE” link, and noticed DHCP was also enabled in HA. I disabled it, and set to static, seeing that my router has DHCP enabled. I rebooted HA NUC. But, still can not install Add-ons.

Still get same error


What are your DNS settings, not DHCP?

OK, sorry, it is Should be correct, that is my secondary router’s LAN IP = Gateway.

I changed DNS Servers to, and now it works. Thanks a lot for the help? Is this the best option, or should I use something else?

I suspect your DNS server is on the primary router. Try setting the DNS server to that. The gateway should forward it.

That didn’t go too well. I changed DNS server in HA to IP of primary router = And, now I have the same problem again. And, the “CHANGE” setting next to IP address is missing. So, can not change it back to “” any more. Any help how to change it back again?

My logs show

21-08-03 14:19:00 WARNING (MainThread) [supervisor.resolution.evaluations.base] NetworkManager is not correctly configured (more-info:
21-08-03 14:19:01 WARNING (MainThread) [supervisor.core] System running in a unsupported environment!

And, as mentioned on top the “CHANGE” link and “IP Address” section is now missing. It obviously did not like the DNS setting I entered. Any idea how to change the DNS setting back to “” with out the UI ?

Have you tried gong to the Home Assistant IP address?

Do you have ssh access or can you connect a monitor and keyboard to Home Assistant?

Hi, I can still access HA webpage. But, in “Supervisor → System” it does not show my IP any more, and no “CHANGE” button.

Yes, I have access to monitor and keyboard on my HA NUC. I have been looking at commands, but can not find way to reset DNS Servers.

Try clearing your browser cache first - the HA web page can get “stuck” sometimes and clearing cache has solved many a problem.

Did that, and tried on different browser, still menu item not there

At the home assistant cli:

ha dns options --servers dns://IP_ADDRESS
ha dns restart

Hi, I did that, but still not working. Also rebooted NUC, and cleared cache on browser.

HA in your case should use:
netmask is not clear from your info
dns or or (these should all work)

As far as i can see, you used the wrong gateway, ha wouldn’t have a clue where is, as it is not on the same LAN :wink:

What does this show?

ha dns info