AP offline on Nebula



We’d like to use Nebula cloud for management because I knew the benefit such as APP and wireless health auto optimization features.


We’re facing an issue that we’ve registered and added the AP into the site via nebula APP, but the AP keeps showing offline on NCC and its LED flashing in Yellow/Green status after connecting it to the network.

AP is NWA1123ACv3.


Best Regards,


Accepted Solution

  • Zyxel_Bella
    Zyxel_Bella Posts: 139  Zyxel Employee
    Accepted Answer

    Hi IT_Patty,


    The LED flashing in yellow and green status stands for the AP is searching for Nebula. In this case, it’s most likely the call-home (to Nebula) connection was being blocked either by your firewall or your ISP! You can connect to the default SSID broadcasted by AP named in “Zyxel-XXXX”, last four letters of the device MAC address.

    You can just type this URL in your browser http://setup.zyxel and it will lead you to the AP admin page.

    Since the AP is not online on Nebula yet. You have to enter default account: admin, password: 1234 to login local GUI.

    You can find Nebula Control Center Status at CONFIGURATION > Network > NCC Discovery. If you see, “This AP is connected to the internet”, it means there’s no problem for your LAN & Internet. “This access point is not connected to the Nebula” means the AP call-home (to Nebula) connection is somehow not successful. In most cases, it’s the TCP/UDP port being blocked by your local firewall or your ISP.


    The following table lists the TCP/UDP ports used by Nebula devices, please check your firewall or ISP if they’re blocking them.


All Replies

  • Hi,
    Thanks for the hints. My client’s using a normal router, and it’s his ISP blocking the TCP 4335 & 6667. His ISP finally agreed to open up TCP 4335 and everything works fine!

    Best Regards,