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RT-AC86U with Merlin 384.14_2 - Nest Thermostat cannot connect? [Solved]

Discussion in 'Asuswrt-Merlin' started by Rici, Jan 18, 2020.

  1. Rici

    Rici New Around Here

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    Hi all,

    After I took out my old RT-AC68U running Merlin, where my Nest Thermostat had no problem connecting to, I cannot get it to connect to my new RT-AC86U running Merlin 384.14_2.

    As it looks like it gets the DHCP information from the router, but cannot communicate with the Internet.

    Are there any tricks that I can use for making my Nest Thermostat working again?

    Thanks for helping me.
     
    Last edited: Jan 18, 2020
  2. EventPhotoMan

    EventPhotoMan Very Senior Member

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    What trouble shooting steps have you taken so far?
     
  3. Rici

    Rici New Around Here

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    Everything that I can think of :)

    Rebooted the router, the Nest as well, set the 2.4Ghz WiFi on the router to 20Mhz only, enabled/disabled Bluetooth there - but no change.

    The Nest gets the DHCP Infos, but cannot communicate with the Internet. Ping, according to Nest, remains at Zero ms.
     
  4. EventPhotoMan

    EventPhotoMan Very Senior Member

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    Can you control nest thermostat via wifi or LTE?
     
  5. Rici

    Rici New Around Here

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    Nope, both the Nest app and web interface tell me my thermostat is offline.
     
  6. rwe

    rwe New Around Here

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  7. Rici

    Rici New Around Here

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    That's something I checked already.

    And with my former router it worked.

    Is the something specific with Merlin 384.14 and Nest Thermostat that causes this strange behavior?
     
  8. Crazy

    Crazy Occasional Visitor

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    Turn off “Airtime fairness” for 2.4 Ghz.
     
  9. ewokuk

    ewokuk Occasional Visitor

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    I had a similar problem with a few devices when I tried to use DoT with nextdns, at first they seemed ok but after a while (not sure how long, a few minutes or an hour maybe) they would be connected fine but have no internet access. It was something to do with nextdns over DoT because switching it to DoT with 1.1.1.1 instead, it hasnt happened since. If you are using the built in DNS-over-TLS then it might be related to that.
     
  10. EventPhotoMan

    EventPhotoMan Very Senior Member

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    The next step I would do is set up your nest thermostat is a new device again, because if it doesn’t connect there then you definitely have a problem
     
  11. Rici

    Rici New Around Here

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    So, DHCP and Wifi connection between the Merlin router and the Nest thermostat is working.

    But: Still Nest cannot communicate with its cloud service - so I cannot control the thermostat with the app from remote.

    Is Asus/Merlin - or Diversion / SkyNet - blocking the communication of the thermostat with the Nest cloud servers?

    How to trace that down and find out?
     
  12. EventPhotoMan

    EventPhotoMan Very Senior Member

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    Ping the nest cloud with another device.
     
  13. CaptainSTX

    CaptainSTX Part of the Furniture

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    To solve if it is Skynet use the option to temporarily disable using option 9, then reboot your router and confirm Skynet is inactive and then try and reconnect.
     
    Kingp1n likes this.
  14. Kingp1n

    Kingp1n Senior Member

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    If you're using a VPN...you might need to disable that too temporarily.
     
  15. Marin

    Marin Very Senior Member

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    I have never had any issues using my Nest thermostat when I had an AC86U or now with my AX88U. I have used Skynet and NordVPN all along and other scripts and they never impacted its function.


    Sent from my iPhone using Tapatalk
     
  16. SheikhSheikha

    SheikhSheikha Regular Contributor

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    With Nest Protect I have the experience that they require a complete new configuration (after a full reset) before they work stabile with a new router firmware. Perhaps the same is applicable to the thermostat?
     
    L&LD likes this.
  17. Rici

    Rici New Around Here

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    Hi folks, thanks for all your hints.

    While I could not determine a root cause, it was definitely caused by a combination of Diversion and DNS Server settings.

    As soon as I disabled Diversion and enabled DNS Filtering with providing my Nest Thermostat a particular DNS server (1.1.1.1 in my case), my Nest became accessible by the app and web again.

    So it's working now, issue solved.
     
    EventPhotoMan and Kingp1n like this.