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FortiClient WAN optimization over IPsec VPN configuration example

FortiClient WAN optimization over IPsec VPN configuration example

This example shows how to add WAN optimization to a FortiClient IPsec VPN. The IPsec VPN tunnel allows remote FortiClient users to connect to the internal network behind the FortiGate unit.


Example FortiClient WAN optimization configuration

To configure the FortiGate unit

Because computers running FortiClient can have IP addresses that change often, it is usually not practical to add FortiClient peers to the FortiGate WAN optimization peer list. Instead, a FortiGate unit that accepts WAN optimization tunnel requests from FortiClient is usually configured to accept any peer. This example does this by adding a WAN optimization authentication group with Peer acceptance set to Accept Any Peer.

In addition this example includes a wanopt to internal policy to allow WAN optimization traffic reach the internal network. Finally passive WAN optimization is added to the ssl.root policy because WAN optimization is accepting traffic from the IPsec VPN tunnel.

1. Go to WAN Opt. & Cache > Authentication Groups and select Create New.

2. Configure the WAN optimization authentication group:


Name                                           auth-fc

Authentication Method            Certificate

Certificate                                   Fortinet_Firmware

Peer Acceptance                       Accept Any Peer

3. Select OK.

4. Go to WAN Opt. & Cache > Profiles and select Create New (select the + button).

5. Add a profile for FortiClient WAN optimization sessions:

Name                                           Fclient_Pro

Transparent Mode                    Select

Authentication Group              auth-fc


Category                                     Address

Address Name                           Internal-Server-Net

Type                                            IP Range

Subnet / IP Range           

Interface                                     internal

9. Enter the following CLI command to add an explicit proxy policy to accept WAN optimization tunnel connections.

configure firewall explicit-proxy-policy edit 0

set proxy wanopt

set dstintf internal set srcaddr all

set dstaddr all set action accept set schedule always set service ALL

next end


To set up IPsec VPN to support WAN optimization

1. Go to VPN > IPsec Wizard, enter a Name for the IPsec VPN and select Dialup – FortiClient (Windows, Mac OS, Android).

2. Follow the wizard steps to configure the VPN. No special WAN optimization settings are required.

3. Go to Policy & Objects > IPv4 Policy and edit the policy created by the wizard.


This policy has the IPsec VPN interface created by the wizard as the source interface.

4. Turn on WAN Optimization and configure the following settings:


Enable WAN Optimization       passive

Passive Option                          default

5. Select OK.


To configure FortiClient and start the WAN optimization SSL VPN connection

1. Open FortiClient, configure Advanced settings, and select Enable WAN optimization.

2. Add a new IPsec VPN connection.


Set the Server to the WAN1 IP address of the FortiGate unit ( in this example).

No other settings are required for this example. You can add authentication in the form of a user name and password if required by the FortiGate unit.

3. Start the IPsec VPN tunnel.


You should be connected to the IPsec VPN tunnel and traffic in it should be optimized.