How do I block Tor browsing with Smoothwall?

Article #: Product Castle
KB-27   None


A guide to blocking users from Tor browsing to avoid filtering.


The Tor browser allows users to browse in privacy, obscuring content from the web filter and allowing receipt of unfiltered traffic. While the user may perceive this as a benefit, enabling them to access content which may otherwise be restricted by their school or employer, this can present a real risk within any institution, particularly a school or other environment with young or vulnerable users.


Tor is freeware which is developed and run by volunteers. Users can download the browser to their device or run it from a USB drive, allowing the user to take it with them onto devices within the protected network. Once accessed, the browser obscures the traffic by hiding it among the traffic of all other Tor users, masking the user’s location. The software also allows them to create an undetectable tunnel out to the internet, enabling them to bypass filtering and reporting of their browsing.

Tor may be blocked by enabling layer 7 filtering on the master Smoothwall device. You need to edit the customer’s current layer 7 filtering policies under Networking > Outgoing > Ports. Hover over Blocked services to bring up the list of Layer 7 categories, and click Edit. Tor can be found under the Proxies section.


Last updated: Author: Contributions by:
23 August 2017 Suzanne Knight