FortiGate
FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
jhussain_FTNT
Article Id 206619
Description This article describes how to clear the unit inventory in particular frequent interval via the automated script.
Scope  
Solution

Units that were automatically discovered by FortiGate will expire in 28 days by default if FortiGate does not see the unit in the network anymore.

 

Following  automated script is  to clear the unit inventory in every 8 hours.

 

# config system auto-script
    edit "cleardeviceuser"
        set interval 28800
        set repeat 0
        set script "
# diagnose user device clear"
next
end

 

If incase of VDOM and need to clear in particular VDOM.

 

# config system auto-script
    edit "cleardeviceuser"
        set interval 28800
        set repeat 0
        set script "
# config vdom
    edit <vdom name>
# diagnose user device clear"
next
end