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GCP Administration Guide

Configuring the tunnel interfaces

Configuring the tunnel interfaces

The following instructions use the 169.254.110.0/29 subnet. This subnet is used only inside the site-to-site tunnel. You use the IP addresses assigned in this configuration to configure BGP neighbors.

To configure the tunnel interface on the spoke 1 FortiGate to the remote site 1 FortiGate:
  1. On the spoke 1 FortiGate, go to Network > Interfaces.
  2. Extend the port 1 interface to reveal a new tunnel interface.
  3. Edit the tunnel interface:
    1. In the IP field, enter the local tunnel IP address. In this example, the value would be 169.254.110.1, the spoke 1 FortiGate IP address.
    2. In the Remote IP/Netmask field, enter the remote tunnel IP address with netmask. In this example, the value would be 169.254.110.2 255.255.255.248. 169.254.110.2 is the remote site 1 FortiGate IP address, and 255.255.255.248 is the netmask.
    3. Configure other settings as your network requires.
    4. Click OK.

To configure the tunnel interface on the remote site 1 FortiGate to the spoke 1 FortiGate:
  1. On the remote site 1 FortiGate, go to Network > Interfaces.
  2. Extend the port 1 interface to reveal a new tunnel interface.
  3. Edit the tunnel interface:
    1. In the IP field, enter the local tunnel IP address. In this example, the value would be 169.254.110.2, the remote site 1 FortiGate IP address.
    2. In the Remote IP/Netmask field, enter the remote tunnel IP address with netmask. In this example, the value would be 169.254.110.1 255.255.255.248. 169.254.110.2 is the spoke 1 FortiGate IP address, and 255.255.255.248 is the netmask.
    3. Configure other settings as your network requires.
    4. Click OK.

Configuring the tunnel interfaces

Configuring the tunnel interfaces

The following instructions use the 169.254.110.0/29 subnet. This subnet is used only inside the site-to-site tunnel. You use the IP addresses assigned in this configuration to configure BGP neighbors.

To configure the tunnel interface on the spoke 1 FortiGate to the remote site 1 FortiGate:
  1. On the spoke 1 FortiGate, go to Network > Interfaces.
  2. Extend the port 1 interface to reveal a new tunnel interface.
  3. Edit the tunnel interface:
    1. In the IP field, enter the local tunnel IP address. In this example, the value would be 169.254.110.1, the spoke 1 FortiGate IP address.
    2. In the Remote IP/Netmask field, enter the remote tunnel IP address with netmask. In this example, the value would be 169.254.110.2 255.255.255.248. 169.254.110.2 is the remote site 1 FortiGate IP address, and 255.255.255.248 is the netmask.
    3. Configure other settings as your network requires.
    4. Click OK.

To configure the tunnel interface on the remote site 1 FortiGate to the spoke 1 FortiGate:
  1. On the remote site 1 FortiGate, go to Network > Interfaces.
  2. Extend the port 1 interface to reveal a new tunnel interface.
  3. Edit the tunnel interface:
    1. In the IP field, enter the local tunnel IP address. In this example, the value would be 169.254.110.2, the remote site 1 FortiGate IP address.
    2. In the Remote IP/Netmask field, enter the remote tunnel IP address with netmask. In this example, the value would be 169.254.110.1 255.255.255.248. 169.254.110.2 is the spoke 1 FortiGate IP address, and 255.255.255.248 is the netmask.
    3. Configure other settings as your network requires.
    4. Click OK.