Changing the base management subnet and VLAN
You can change the base management subnet from the FortiController GUI by going to Load Balance > Config and changing the Internal Management Network.
You can also change the base management subnet and VLAN ID from the FortiController CLI. For example, use the following command to change the base management subnet to 10.121.10.0 and the VLAN to 131:
config load-balance setting
set base-mgmt-internal-network 10.121.10.0 255.255.255.0
config base-mgt-interfaces
edit b1
set vlan-id 131
next
edit b2
set vlan-id 131
end
If required, you can use different VLAN IDs for the B1 and B2 interface.
Changing this VLAN only changes the VLAN used for base management traffic between chassis. Within a chassis the default VLAN is used.