Special configuration required for SSL VPN
Using a FortiGate-6000 or 7000 as an SSL VPN server requires you to manually add an SSL VPN load balance flow rule to configure the FortiGate-6000 or 7000 to send all SSL VPN sessions to the primary (master) FPC (FortiGate-6000) or the primary (master) FPM (FortiGate-7000). 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. A basic rule to allow SSL VPN traffic could be:
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 worker"
next
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 worker"
end
Adding the SSL VPN server IP address
You can add the IP address of the FortiGate-6000 or 7000 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 worker"
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 or FPM.