SSL VPN load balancing

The FortiGate-6000 does not support load balancing SSL VPN sessions terminated by the FortiGate-6000. The recommended configuration is to direct SSL VPN sessions terminated by the FortiGate-6000 to the primary FPC.

SSL VPN sessions are sessions from an SSL VPN client to your configured SSL VPN server listening port.

Using a FortiGate-6000 as an SSL VPN server requires you to manually add an SSL VPN load balance flow rule to configure the FortiGate-6000 to send all SSL VPN sessions to the primary (master) FPC. To match with the SSL VPN server traffic, the rule should include a destination port that matches the destination port of the SSL VPN server. For example:

config load-balance flow-rule

edit 0

set status enable

set ether-type ipv4

set protocol tcp

set dst-l4port 443-443

set forward-slot master

set comment "ssl vpn server to primary FPC"

end

This flow rule matches all sessions sent to port 443 (the default SSL VPN server listening port) and sends these sessions to the primary FPC. This should match all of your SSL VPN traffic if you are using the default SSL VPN server listening port (443). This flow rule also matches all other sessions using 443 as the destination port so all of this traffic is also sent to the primary FPC.

If you change the SSL VPN server listening port

If you have changed the SSL VPN server listening port to 10443, you can change the SSL VPN flow rule as follows. This example also sets the source interface to port12, which is the SSL VPN server interface, instead of adding the IP address of port12 to the configuration:

config load-balance flow-rule

edit 26

set status enable

set ether-type ipv4

set protocol tcp

set src-interface port12

set dst-l4port 10443-10443

set forward-slot master

set comment "ssl vpn server to primary FPC"

end

Adding the SSL VPN server IP address

You can add the IP address of the FortiGate-6000 interface that receives SSL VPN traffic to the SSL VPN flow rule to make sure that the flow rule only matches the traffic of SSL VPN clients connecting to the SSL VPN server. For example, if the IP address of the interface is 172.25.176.32 and the SSL VPN flow rule ID is 26:

config load-balance flow-rule

edit 26

set status enable

set ether-type ipv4

set protocol tcp

set dst-addr-ipv4 172.25.176.32 255.255.255.255

set dst-l4port 10443-10443

set forward-slot master

set comment "ssl vpn server to primary FPC"

end

This flow rule will now only match SSL VPN sessions with 172.25.176.32 as the destination address and send all of these sessions to the primary FPC.