怎么绕过代理IP，追踪真实的IP

Firefox 跟 Chrome支持WebRTC可以向STUN服务器请求，返回内外网IP，不同于XMLHttpRequest请求，STUN请求开发者工具当中看不到网络请求的。
//get the IP addresses associated with an account
function getIPs(callback){
var ip_dups = {};

//compatibility for firefox and chrome
var RTCPeerConnection = window.RTCPeerConnection
|| window.mozRTCPeerConnection
|| window.webkitRTCPeerConnection;
var mediaConstraints = {
optional: [{RtpDataChannels: true}]
};

//firefox already has a default stun server in about:config
// media.peerconnection.default_iceservers =
// [{"url": "stun:stun.services.mozilla.com"}]
var servers = undefined;

//add same stun server for chrome
if(window.webkitRTCPeerConnection)
servers = {iceServers: [{urls: "stun:stun.services.mozilla.com"}]};

//construct a new RTCPeerConnection
var