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GCP Administration Guide

Configuring static addressing in FortiOS

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Configuring static addressing in FortiOS

Note

You must following the proper order of actions as documented. Changing interface settings before configuring routing results in loss of communication with the FortiGate, which you can recover using CLI commands over a serial console.

To configure static addressing in FortiOS:
  1. Log in to the FortiOS GUI.
  2. Go to Network > Static Routes.
  3. Configure a route to the first IP address in the subnet with a netmask of 255.255.255.255:
    1. Click Create New.
    2. In the Destination field, enter the desired subnet.
    3. For Gateway Address, select Specify. Enter 0.0.0.0.
    4. From the Interface dropdown list, select the desired interface.
    5. Click OK.
  4. Configure a route to the local subnet CIDR:
    1. Click Create New.
    2. In the Destination field, enter the desired subnet.
    3. For Gateway Address, select Specify. Enter the first IP address in the subnet. In this example, it is 10.132.0.1. The FortiOS GUI displays a warning that the gateway IP address is unreachable via the interface. You can disregard this error, as the first configured route mitigates it.
    4. From the Interface dropdown list, select the desired interface.
    5. Click OK.

  5. If you are configuring the port1 interface, which FortiOS typically uses for egress traffic to the Internet, metadata service, and the Google API, you must configure a default route using gateway settings:
    1. Click Create New.
    2. In the Destination field, enter 0.0.0.0/0.0.0.0.
    3. For Gateway Address, select Specify. Enter the same IP address configured as the gateway address for the route to the local subnet CIDR. In this example, it is 10.132.0.1.
    4. From the Interface dropdown list, select port1.
    5. Click OK.

  6. Go to Network > Interfaces.
  7. Double-click the desired interface.
  8. Under Addressing mode, select Manual. FortiOS automatically populates the proper IP address with a 255.255.255.255 netmask.
  9. Click OK.

Configuring static addressing in FortiOS

Note

You must following the proper order of actions as documented. Changing interface settings before configuring routing results in loss of communication with the FortiGate, which you can recover using CLI commands over a serial console.

To configure static addressing in FortiOS:
  1. Log in to the FortiOS GUI.
  2. Go to Network > Static Routes.
  3. Configure a route to the first IP address in the subnet with a netmask of 255.255.255.255:
    1. Click Create New.
    2. In the Destination field, enter the desired subnet.
    3. For Gateway Address, select Specify. Enter 0.0.0.0.
    4. From the Interface dropdown list, select the desired interface.
    5. Click OK.
  4. Configure a route to the local subnet CIDR:
    1. Click Create New.
    2. In the Destination field, enter the desired subnet.
    3. For Gateway Address, select Specify. Enter the first IP address in the subnet. In this example, it is 10.132.0.1. The FortiOS GUI displays a warning that the gateway IP address is unreachable via the interface. You can disregard this error, as the first configured route mitigates it.
    4. From the Interface dropdown list, select the desired interface.
    5. Click OK.

  5. If you are configuring the port1 interface, which FortiOS typically uses for egress traffic to the Internet, metadata service, and the Google API, you must configure a default route using gateway settings:
    1. Click Create New.
    2. In the Destination field, enter 0.0.0.0/0.0.0.0.
    3. For Gateway Address, select Specify. Enter the same IP address configured as the gateway address for the route to the local subnet CIDR. In this example, it is 10.132.0.1.
    4. From the Interface dropdown list, select port1.
    5. Click OK.

  6. Go to Network > Interfaces.
  7. Double-click the desired interface.
  8. Under Addressing mode, select Manual. FortiOS automatically populates the proper IP address with a 255.255.255.255 netmask.
  9. Click OK.