ValdikSS/openvpn-fix-dns-leak-plugin

OpenVPN plugin to fix Windows DNS Leaks

Windows 10 DNS resolver sends DNS requests in parallel to all available network interfaces and uses the fastest reply to come. If you use DNS from the local network, this problem allows your ISP or a hacker with Wi-Fi ap to hijack your DNS records and steal your data even if you use VPN .

This plugin should fix this issue for Windows 8.1 and Windows 10 users. Read More.

How to use

Functionality of this plugin is integrated into OpenVPN 2.3.9, just use --block-outside-dns configuration option. If you can't use the latest OpenVPN version, follow the steps below:

1. Download fix-dns-leak-32.dll for 32 bit system or fix-dns-leak-64.dll for 64 bit system
2. Add the following line to your OpenVPN configuration file:
   plugin fix-dns-leak-32.dll
   for 32 bit system or
   plugin fix-dns-leak-64.dll
   for 64 bit system

How it works

This plugin implements Windows Filtering Platform userspace filter to block all IPv4 and IPv6 DNS queries from DNS Client service to port 53 except on OpenVPN's TAP interface. It works like a temporary firewall which clears its rules upon termination or crash. This is important as you won't get broken internet connection if OpenVPN client suddenly crashes, unlike with other methods.