Fortinet FortiGate-800 Configuring redundant IPSec VPNs, 254, To configure a redundant IPSec VPN

Redundant IPSec VPNs IPSec VPN

Configuring redundant IPSec VPNs

Prior to configuring the VPN, make sure that both FortiGate units have multiple connections to the Internet. For each unit, first add multiple (two or more) external interfaces. Then assign each interface to an external zone. Finally, add a route to the Internet through each interface.

Configure the two FortiGate units with symmetrical settings for their connections to the Internet. For example, if the remote FortiGate unit has two external interfaces grouped in one zone, then the local FortiGate unit should have two external interfaces grouped in one zone. Similarly, if the remote FortiGate has two external interfaces in separate zones, then the local FortiGate unit should have two external interfaces in separate zones.

The configuration is simpler if all external interfaces are grouped in one zone, rather than multiple zones. However, this might not always be possible because of security considerations or other reasons.

After you define the Internet connections for both FortiGate units, you can configure the VPN tunnel.

To configure a redundant IPSec VPN

1Add the phase 1 parameters for up to three VPN connections.

Enter identical values for each VPN connection, with the exception of the Gateway Name and IP Address. Make sure that the remote VPN peer (Remote Gateway) has a static IP address.

See “Adding a phase 1 configuration for an AutoIKE VPN” on page 235.

2Add the phase 2 parameters (VPN tunnel) for up to three VPN connections.

•If the Internet connections are in the same zone, add one VPN tunnel and add the remote gateways to it. You can add up to three remote gateways.

•If the Internet connections are in separate zones or assigned to unique interfaces, add a VPN tunnel for each remote gateway entered.

See “Adding a phase 2 configuration for an AutoIKE VPN” on page 240.

3Add the source and destination addresses. See “Adding a source address” on page 246. See “Adding a destination address” on page 247.

4Add encrypt policies for up to three VPN connections.

•If the VPN connections are in the same zone, add one outgoing encrypt policy; for example an Internal->External policy. Add the AutoIKE key tunnel to this policy.

•If the VPN connections are in different zones, add a separate outgoing encrypt policy for each connection. The source and destination of both policies must be the same. Add a different AutoIKE key tunnel to each policy.

See “Adding an encrypt policy” on page 247.

254 Fortinet Inc.