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GCP Administration Guide

Configuring the tunnel interfaces

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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 will 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

The following instructions use the 169.254.110.0/29 subnet. This subnet is used only inside the site-to-site tunnel. You will 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.