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Article Id 189830
This article explains how to block TurboVPN for the mobile users.

Turbo VPN is a popular free VPN proxy client for Android and iOS. Google Play reports the app has had more than 50 million installs, and it's easy to see why. The free service gives access to nine servers across North America, Europe and Asia, and there are no bandwidth limits or restrictions.

For starters, they use the best-in-class OpenVPN tunnelling protocol. It’s an open sourced system, so it’s kept up to date by a vast community watching each other’s backs.

Paired with OpenVPN is government-level AES-256 encryption.

Some users can try to bypass the Firewall by using TurboVpn to use the sites which are blocked internally in the network.

For the network safety and to control the users from accessing the Websites that are blocked by the Firewall, it is possible to block the working of TurboVpn.

Basically application TurboVpn signature on FortiOS is there, however to block this application, it is required to block the dependent application as well. In this case that is ISAKMP.

Create an Application control profile or Edit the default.

Add the 2 applications to the application override and set action to block.

Note: Make sure the inspection mode is Proxy and inspection in IPv4 policy is set to deep inspection mode.