By default, GCP assigns a VM instance an ephemeral internal IP address every time it is started. Before you configure a static IP address in FortiOS, ensure that Google Compute will always use the same IP address.
- Open VM instance details for the FortiGate.
- Click Edit.
- Under Network interfaces, click the pencil icon to edit a desired network interface's properties.
- From the Internal IP type dropdown list, select Static. This reserves the currently used internal IP address. This option is only available for instances that are currently running. You can assign a custom internal IP address for a stopped instance by changing its NIC properties.
- Enter a name for the reserved internal IP address.
- Repeat steps 3-6 for all desired network interfaces.