VPN Tunnel Settings

In the conference for the VPN tunnel the following advice is given:

“If you are going to use the non-firewalled secure server, download a good software firewall and set the Secure VPN to “internet” zone, not “trusted” zone.”

I am using the non firewalled servers because the firewalled ones do not work well with bittorrents.

How can I ensure that the Secure VPN server is not ia trusted zone?