Issue with IKEA Home Smart Gateway
Whenever I am using NextDNS with default settings, my Ikea HomeSmart Gateway refuses to work after a couple of minutes. Restarting it helps to get it running again for a while.
Issue is, that neither homekit nor cell phone app are able to reach the Ikea Gateway anymore in the same intranet 192.168.x.x.
After changing back the DNS servers to provider‘s defaults everything works fine again.
Any help would be appreciated.
As the problem occured after several day again, that the Gateway was not reachable from intranet anymore, I researched the network traffic and IKEA related forums deeper.
After analyzing my router's logs, I discovered, that the IKEA Tradfri Gateway retries to reach Google DNS (18.104.22.168) and Amazon Servers (e.g. 22.214.171.124, 126.96.36.199 and 188.8.131.52), periodically.
But no matter what I try for NEXTDNS settings (already mentioned in posts above --> disabled rebind protection / DNS bypass blocking as well as adding those servers to Allow-List), the device becomes unreachable from intranet after approx. 2 days in operation. Seems like it blocks access from internal.
So I found in some IKEA related forums that this behavior seems to be a bug by the device itself.
The suggestion is to completely disable the Tradfri Gateway's WWW (internet access) by the Main router (so intranet LAN access remains active). This is what I am trying currently, seems to be successfull. This doesn't interfere with the IKEA app's or Tradfri Gateway's functionality, as anyhow now Internet-Access to the device is possible (only by Apple's Homekit or Amazon Alexa).
However, I can conclude, that the "no connect issue" of IKEA's Tradfri gateway doesn't occur that regular with using my Internet provider's DNS default servers, but occurs approx. evers 2 days with using NEXTDNS's DNS servers (and default profile settings). Turning off internet access of this device seems to help. Unclear for me, what the technical reason is?