202121 - Device Not Registered in the ADOM

Agent error code #202121 indicates that the target device is not present in the ADOM the knoc is configured to use. FortiManager found the ADOM and does not have that device in it.

Common causes include:

• The device name on the knoc does not match its name in FortiManager
• The device is registered in a different ADOM
• The device was removed from FortiManager after the knoc was configured
• The device is registered but is a model device that has never checked in

Steps to Resolve

Confirm the Device Name

1. In FortiManager, select the ADOM configured on the knoc
2. Go to Device Manager > Device & Groups
3. Note the device name exactly as FortiManager shows it. This is the name FortiManager knows it by, which is not always its hostname
4. Enter that name in the Knocknoc backend configuration

Confirm It Is in the Right ADOM

Switch between ADOMs in FortiManager and confirm which one holds the device. If it is in a different ADOM from the one on the knoc, correct whichever is wrong. See #202120 for the ADOM field.

Confirm the Device Is Connected

1. In Device Manager, check the device's connection status
2. A device showing as unregistered or never connected cannot receive the dynamic entry

Run the Knoc Validator

Open the knoc and run Validate. The agent lists the devices it can see in the configured ADOM and suggests a value for the field.