Zyxel Switch NNC [Nebula] - Stabilise Cloud Auto Configuration Recovery

What Is Auto Configuration Recovery?

Auto Configuration Recovery is a safety mechanism that reverts a switch back to its last known good configuration (also referred to as the custom default) if the device fails to successfully “call home” (i.e., communicate with Nebula) after receiving a configuration update.

This mechanism is triggered during a monitor period that follows a NETCONF-based configuration provisioning. If the switch cannot verify its registration or complete synchronisation with the Nebula Control Centre (NCC) within this period, it will automatically roll back to the previous stable configuration to maintain network availability.

Side Effects of Applying Configurations

One notable side effect of configuration updates is related to Power over Ethernet (PoE). When a switch undergoes a configuration push that involves PoE settings, the following may occur:

• PoE devices may reboot as a result of the switch performing a PoE OFF → ON sequence.
  This behavior is expected and should be considered when planning updates, particularly in networks with critical PoE-powered devices such as IP phones or security cameras.

Which Actions Count as NETCONF Provision?

NETCONF provisioning occurs whenever NCC sends configuration or status updates to the switch. These actions include:

• User-applied switch settings via the Nebula Control Center:
  All changes made by users in the NCC are compiled and sent to the switch as NETCONF configurations.
• Scheduled firmware upgrades:
  NCC uses NETCONF as a mechanism to trigger and manage device firmware upgrades.
• Periodic device registration updates:
  NCC periodically informs the device of its registration status using NETCONF.
• Device (re)connections to Nebula:
  When a switch connects or reconnects to the NCC, the following updates are automatically pushed via NETCONF:
  • Updated NTP Server 1 and NTP Server 2
  • Updated ACL (Access Control List) rules for cloud management

Activate or Deactivate auto-configuration recovery

To enable Auto Configuration Recovery Go to:

Navigate to Site-wide > Configure > Switches > Switch settings.

An "Auto Configuration Recovery" message in Nebula typically indicates that a device, in this case a Nebula-enabled switch, has detected a configuration problem and is attempting to automatically recover or revert its configuration to a known, stable state.
 

 
Click on the "Change Log" button ,and the system will redirect you to the Change Log page, which will display all configuration changes made during the last half an hour before locking the device. You can press the unlock button once the configuration error has been corrected.

Summary

The Stabilise Cloud Auto Configuration Recovery feature ensures that your switches maintain operational stability by automatically recovering from failed configurations. Understanding what actions trigger NETCONF provisioning—and which of those initiate the monitor period—helps in planning updates and minimizing unintended impacts on your network.