Zyxel nebula dashboard says switches are offline

Lorcan · July 2022

Hi, I believe the information on the zyxel nebula website is incorrect.

We have all 4 switches online, by this I mean they are working as switches within our internal LAN. PCs, phones, printers, etc. are all connected to the 4 switches we have. And the devices are assigned IPs by an ISP modem connected to the switch.

What is strange is that the Nebula dashboard says the switches are offline.

Does anyone know why that is?

Zyxel_Adam · July 2022

Hi Lorcan,

Thanks for sharing this information.

May we know if NCC Dashboard of your site still shows offline for all switches?
If so, please provide us your Organization name and enable Zyxel support at Help > Support request page (enable it and click SAVE button) so that we will be able to access your organization then check the issue.

Image: https://us.v-cdn.net/6029482/uploads/editor/54/qssekbl1k1iu.png

SLMark1 · July 2022

We see this all the time when the primary DNS is not responding in a network. A good example is if there is a DC in the network and it is offline. The nebula hardware does not seem smart enough to move to the second DNS option under the DHCP configuration. We are leaning towards starting to statically assign all the network hardware because of this. Something we stopped doing years ago. It is a major issue if you ask me. We get false down alerts all the time.

Zyxel_Adam · July 2022

Hi @SLMark1,

Thanks for sharing this information.

Our switch has the same behavior in either DHCP or Static IP configuration, so once switch is unable to get a reply from first DNS server, it sends packet to both DNS address you configured and see which DNS server respond to switch first.

May we know how do you determine that your primary DNS is not responding to your network?
May we know if you use local DNS address as switch first DNS?

SLMark1 · September 2022

Sorry for the late response. Switches do not move to DNS2 when DNS1 is down. Every client we have with local DNS has this issue. This is true even if the device is rebooted and or defaulted. If defaulted a switch will check in to Nebula for just a second, but then switch to an offline status with Nebula, however, the switch itself is working and the connected devices are online.

Lorcan · October 2022

Hi I am having this problem again. Does anyone have a solution for this?

I can't modify the config on the switches because they are "offline" despite working properly and giving switching to our network? So the switches are connected to devices and are supplying the devices power and internet connection - yet the switches themselves cannot connect to the internet?

Lorcan · October 2022

Another bit of info that might help, we also have 2 Zyxel APs. Both of them are connected to the Zyxel Nebula cloud. Its just the switches that are seen as offline.