Leakage" usually refers to two situations: First, all traffic is encrypted using a VPN, but DNS requests bypass this secure channel.
This kind of leakage is possible if the user manually interferes with the routing and configuration of the VPN. It is solved with configurations prepared by the service and recommended applications.
Second, when using a VPN, the computer keeps contacting the DNS servers of your Internet provider.
This problem is solved by using fast DNS servers, e.g. Cloudflare: 1.1.1.1.
Our applications use DNS 1.1.1.1 by default, but we recommend specifying them additionally in the settings of your main network interface and router. After this, even without VPN, your computer will not contact the DNS servers of your Internet provider.
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