WebRTC is a browser based technology that provides support for optimizing multi-media communications between users. Due to implementation of the protocol some flaws can expose sensitive data of the users such as the real IP address even if they are connected to VPN.You may prevent WebRTC leak on chrome and firefox browsers via below instructions.You may verify WebRTC leakage by visiting https://www.browserleaks.com/webrtc
Chrome
You may use official WebRTC Network limiter plugin released by google below in order to prevent WebRTC Leak.
On Chrome (mobile), please visit URL chrome://flags/#disable-webrtc and enable the option.
Firefox
To disable WebRTC on Firefox for both desktop and mobile version, open about:config, search for media.peerconnection.enabled and double click on it to set it to False.
We also suggest disabling IPv6 usage in order to prevent IPv6 leakage.