Every NymVPN app blocks DNS, WebRTC, and IPv6 leaks by default. If a leak test still shows your real IP or DNS resolver while you're connected, it's almost always a client-side setting or an old app version. Update NymVPN first, then work through the checks below.
What these leaks are
- DNS leak. Your device asks a resolver outside the tunnel (often your ISP's) where a site is, so an observer there sees what you're looking up even though your traffic is encrypted.
- WebRTC leak. Browsers use WebRTC for calls, and it can request your local IP directly, bypassing the VPN. This is a browser issue, not a VPN one.
- IPv6 leak. If your device has IPv6 on but the tunnel only carries IPv4, IPv6 traffic can escape and expose your real IP.
How NymVPN prevents each
DNS queries all go through the tunnel by default (see How to use Domain Name System (DNS) privacy in NymVPN?). The tunnel covers WebRTC, though some browsers add their own WebRTC features (see browser notes below). And NymVPN blocks or routes IPv6 per platform so an IPv4-only tunnel can't leak it.
How to test for a leak
- Connect to NymVPN and confirm it shows "Connected".
- At dnsleaktest.com, run the Extended Test: every DNS server listed should be a NymVPN server, not your ISP.
- At browserleaks.com/webrtc, your "Public IP" should be the NymVPN server IP; a private "Local IP" (like
192.168.x.x) is fine, not a leak. - At ipv6-test.com, "No IPv6 address detected" is expected where IPv6 is blocked; your real IPv6 showing means the tunnel is leaking it.
If a leak shows up
- Update NymVPN; you may be on an old version.
- Restart your device, especially if you've had other VPN clients installed, since leftover routing rules can interfere.
- Disable other VPN, firewall, or proxy software, a frequent cause of conflicts.
Browser-specific notes
-
Firefox: set
media.peerconnection.enabledtofalseinabout:configto disable WebRTC entirely. - Chrome, Brave, Edge: use a browser with WebRTC controls; Brave has built-in toggles under privacy settings.
- Tor Browser: WebRTC is off by default, nothing to do.
If the leak persists
Contact Nym Support with the leak-test URL and a screenshot, your platform and version, your app version, and logs from the affected attempts. All leak reports are prioritized.