How can I block TOR and .onion sites?

DNSFilter is a powerful tool for regulating and securing your organization's digital activities. It operates at the DNS level, meaning it can block access to specific types of harmful or inappropriate content. However, it's important to note that there are certain limitations to what DNSFilter can do.

TOR traffic, for example, can't be halted by DNSFilter. The TOR network (The Onion Router) is a series of servers that allows for anonymous communication over the internet, often used for good purposes, but sometimes misused for illicit activities. Its function is independent of the DNS system, so DNS-based filtering solutions like DNSFilter are not able to prevent TOR traffic.

However, what DNSFilter can do is categorize TOR and .onion sites (which are accessible via the TOR network) on the clear web under the "P2P & Illegal" content category. This means we can prevent users from accessing these sites or their download pages, which could otherwise lead them to obtain the TOR browser. It's a preemptive measure, aimed at reducing the chance of TOR usage within your network.

However, if a user has already installed the TOR browser on their device, they can still access the TOR network when connected to your network. This is a potential loophole, but there are ways to address it. For instance, certain firewalls have the capability to block TOR traffic. We recommend consulting your firewall manufacturer's documentation or seeking expert advice to explore this option. Implementing such a measure could further strengthen your organization's cybersecurity posture and ensure a safer, more controlled internet experience.