Blocking P2P traffic and YouTube applications


In this example, you will learn how to use Application Control to monitor traffic and determine if there are any applications currently in use that should not have network access. If you discover any applications that you wish to block, application control will then be used to ensure that these applications cannot access the network.

1. Enabling Application Control and multiple security profiles

Go to System > Config > Features and ensure that Application Control is turned ON.

Select Show More and enable Multiple Security Profiles.

Apply the changes.

2. Using the default application profile to monitor network traffic

Go to Security Profiles > Application Control and view the default profile.

A list of application Categories is shown. By default, most categories are already set to Monitor. In order to monitor all applications, select All Other Known Applications and set it to Monitor. Do the same for All Other Unknown Applications.

The default profile also has Deep Inspection of Cloud Applications turned ON. This allows web-based applications, such as video streaming, to be monitored by your FortiGate.

3. Adding the default profile to a security policy

Go to Policy & Objects > Policy > IPv4 and edit the policy that allows connections from the internal network to the Internet.

Under Security Profiles, turn on Application Control and use the default profile.

Enabling Application Control will automatically enable SSL Inspection. In order to inspect traffic from Cloud Applications, the deep-inspection profile must be used.

3. Reviewing the FortiView dashboards

Go to System > FortiView > Applications and select the now view.

This dashboard shows the traffic that is currently flowing through your FortiGate, arranged by application (excluding Cloud Applications).

If you wish to know more about an application’s traffic, double-click on its entry to view drilldown information, including traffic sources, traffic destinations, and information about
individual sessions.

Similar information can be viewed for Cloud Applications by going to System > FortiView > Cloud Applications and selecting Applications that have been used in the last 5 Minutes.

Cloud Applications also have drilldown options, including the ability to see which videos have been viewed if streaming video traffic was detected.

5. Creating an application profile to block applications

In the above example, traffic from BitTorrent, a Peer-to-Peer (P2P) downloading application, was detected. Next, you will create an application control profile that will block P2P traffic.

The new profile will also block all applications associated with YouTube, without blocking other applications in the Video/Audio category.


Go to Security Profiles > Application Control and create a new profile.

Select the P2P category and set it to Block.

Under Application Overrides, select Add Signatures.

Search for Youtube and select all the signatures that are shown.

Select Use Selected Signatures.

The signatures have been added to the Application Overrides list and have automatically been set to Block.

Enable Deep Inspection of Cloud Applications.

6. Adding the blocking profile to a security policy

Go to Policy & Objects > Policy > IPv4 and edit the policy that allows connections from the internal network to the Internet.

Set Application Control to use the new profile.

7. Results

Attempt to browse to YouTube. A warning message will appear, stating that the application was blocked.

Traffic from BitTorrent applications will also be blocked.

To see information about this blocked traffic, go to System > FortiView > All Sessions, select the 5 minutes view, and filter the traffic by application.

For further reading, check out Application control in the FortiOS 5.2 Handbook.

Victoria Martin

Victoria Martin

Technical Writer at Fortinet
Victoria Martin works in Ottawa as part of the FortiOS technical documentation team. She graduated with a Bachelor's degree from Mount Allison University, after which she attended Humber College's book publishing program, followed by the more practical technical writing program at Algonquin College. She does need glasses but also likes wearing them, since glasses make you look smarter.
Victoria Martin

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Using the deep-inspection profile may cause certificate errors. For information about avoiding this, see Preventing certificate warnings.
Because Application Control uses flow-based inspection, if you apply an additional security profile to your traffic that is proxy-based, the connection will simply timeout rather than display the replacement message. However, Application Control will still function.