Troubleshooting Tip: Error when creating mgmt interface

An error may occur when using the command 'set interface mgmt' to create a management interface: 

(FG1)# config system interface

(FG1)# edit 1

(1)# set interface "mgmt"

node_check_object fail! for interface mgmt

If the FortiGate is in HA mode:

(FG1)# config system ha

(FG1)# config ha-system-interfaces

(ha-mgmt-interfaces)# edit 1

(1)# set interface "mgmt"

node_check_object fail! for interface mgmt

This is due to an existing database entry with the same name, most likely a static route:

(FG1)#config router static
(FG1)#show full-configuration
(FG1)# edit 1

      set gateway-ip 10.22.8.1
      set device "mgmt"
    next
end

This can be corrected by deleting the static route, provided it is not being used. To clear the static route, use the commands: 

(FG1)# config router static
(FG1)# delete 1
(FG1)# end

Then flush the routing cache with the command:

diagnose ip rtcache flush

The command to set the mgmt interface should work afterward.