Iptables

When running privacy-sensitive applications through a VPN, one of your biggest concerns should be connection drops. If your VPN disconnects unexpectedly, your real IP address gets exposed—defeating the entire purpose of using a VPN in the first place. A VPN kill switch solves this problem by blocking all non-VPN traffic automatically. 💡 This article contains affiliate links. If you buy through them, we earn a small commission at no extra cost to you. Learn more. In this guide, we’ll build a robust, self-hosted VPN kill switch using Docker containers and iptables firewall rules. You’ll learn how to create an isolated network namespace where applications can only communicate through the VPN tunnel—if the VPN drops, all traffic stops completely. We’ll use qBittorrent as our example application, but the same approach works for any Docker container. ...