DNSvuotojen

DNSvuotojen, or DNS leaks, describe a situation in which DNS queries escape the intended protective path and are exposed to outside observers, such as ISPs or DNS providers, even when a VPN or other privacy tool is in use. As a result, the domains visited can be inferred from the DNS traffic, potentially revealing browsing activity and location.

Causes of DNS leaks include VPNs that do not route DNS requests through the VPN, reliance on IPv6 without proper IPv6 DNS handling, WebRTC leaks in web browsers, DNS prefetching, malware, and misconfigured firewall rules or split tunneling that allow non‑VPN DNS traffic.

The primary risks are privacy and security compromises: leakage can reveal which sites are visited, undermine anonymity provided by privacy tools, enable tracking or profiling, and in some environments violate organizational or regulatory requirements.

Detection of DNS leaks is commonly done with online tests that compare the published DNS responses to the user’s apparent location and IP. Running tests with the VPN active and inactive, checking for IPv6 leaks, and validating that DNS queries resolve through the VPN’s DNS servers are typical steps.

Prevention and mitigation strategies include using a VPN that offers DNS leak protection and a kill switch, disabling IPv6 if the VPN does not support it, turning off WebRTC in browsers, enabling DNS over HTTPS or DNS over TLS, and configuring devices or routers to route all traffic through the VPN while blocking non‑VPN DNS queries. Regular testing after changes helps ensure ongoing protection.

See also: DNS over HTTPS, WebRTC, VPN kill switch.