DNS & IP Leak Detection and Fix

Even when connected to a VPN, your real IP address or DNS queries can sometimes "leak" to the outside world. This guide explains how to test for leaks and what to do if you find one.

Step 1: Test for Leaks

With VPNUK connected, visit one of these leak test tools:

ipleak.net dnsleaktest.com browserleaks.com

If the results show your real ISP's IP or DNS servers, you have a leak.

Common Causes & Fixes

DNS Leak (your ISP's DNS servers showing)

In your OpenVPN config, ensure block-outside-dns is set (Windows only)
On Windows: use our VPNUK Software which includes DNS leak protection built-in
Set a custom DNS provider (e.g. Cloudflare 1.1.1.1) in your network settings while on VPN
Disable "Smart Multi-Homed Name Resolution" in Windows Group Policy if present

IP Leak / WebRTC Leak

WebRTC (used by browsers for video calls) can bypass the VPN and reveal your real IP
Install a browser extension such as "WebRTC Leak Shield" or "uBlock Origin" to block WebRTC
Alternatively, disable WebRTC in your browser settings (Firefox: set media.peerconnection.enabled to false in about:config)
Chrome users: install "WebRTC Network Limiter" from the Chrome Web Store

IPv6 Leak

If your ISP supports IPv6 and the VPN only tunnels IPv4, your IPv6 address may show
In your OpenVPN config, add tun-ipv6 or use our config generator to ensure IPv6 is handled correctly
Alternatively, disable IPv6 in your network adapter settings temporarily

Still seeing leaks?

Contact our support team with your leak test results and we'll help you fix the exact configuration.

Submit a Support Ticket