Get local client ipv4 using RTCPeerConnection

localip.js

window.RTCPeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection; //compatibility for firefox and chrome
var pc = new RTCPeerConnection({ iceServers: [] });
var noop = function() {};
pc.createDataChannel(""); //create a bogus data channel
pc.createOffer(pc.setLocalDescription.bind(pc), noop); // create offer and set local description
pc.onicecandidate = function(ice) { //listen for candidate events
  if (!ice || !ice.candidate || !ice.candidate.candidate) return;
  var myIP = /([0-9]{1,3}(\.[0-9]{1,3}){3}|[a-f0-9]{1,4}(:[a-f0-9]{1,4}){7})/.exec(ice.candidate.candidate)[1];
  //sessionStorage.setItem('IP',myIP)
  pc.onicecandidate = noop;
};