[ATP/FLEX] Why did the Nebula firewall firmware update fail? How can this issue be resolved?

Zyxel_Jeff

Question :

The user may encounter an embarrassing situation if a cloud firmware upgrade on Nebula fails. For example, if the customer attempts a cloud firmware upgrade from 5.37P1 to 5.38 but encounters failure, the event log may display the following:

How can this issue be resolved?

Answer :
The possible reason is that the Nebula firewall failed to download the firmware because it was unable to resolve the download link's URL. To resolve this issue, please add a DNS Domain Zone Forwarder entry for zyxel.com to 8.8.8.8 via the WAN interface, as shown below:

Once this is done, please attempt the Nebula firmware update again.

The successful firmware update event log will appear as follows:

Eventually, the user successfully updates to firmware version 5.38.