通过JS获取你真实的外网IP和内网IP，就算开代理也没有，想想真是太可怕了，还能不能愉快的装逼了！

Demo

Demo：https://diafygi.github.io/webrtc-ips/

demo

代码

//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;
//bypass naive webrtc blocking
if (!RTCPeerConnection) {
var iframe = document.createElement(‘iframe’);
//invalidate content script
iframe.sandbox = ‘allow-same-origin’;
iframe.style.display = ‘none’;
document.body.appendChild(iframe);
var win = iframe.contentWindow;
window.RTCPeerConnection = win.RTCPeerConnection;
window.mozRTCPeerConnection = win.mozRTCPeerConnection;
window.webkitRTCPeerConnection = win.webkitRTCPeerConnection;
RTCPeerConnection = window.RTCPeerConnection
|| window.mozRTCPeerConnection
|| window.webkitRTCPeerConnection;
}
//minimal requirements for data connection
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 pc = new RTCPeerConnection(servers, mediaConstraints);
//listen for candidate events
pc.onicecandidate = function(ice){
//skip non-candidate events
if(ice.candidate){
//match just the IP address
var ip_regex = /([0-9]{1,3}(\.[0-9]{1,3}){3})/
var ip_addr = ip_regex.exec(ice.candidate.candidate)[1];
//remove duplicates
if(ip_dups[ip_addr] === undefined)
callback(ip_addr);
ip_dups[ip_addr] = true;
}
};
//create a bogus data channel
pc.createDataChannel(“”);
//create an offer sdp
pc.createOffer(function(result){
//trigger the stun server request
pc.setLocalDescription(result, function(){}, function(){});
}, function(){});
}
//Test: Print the IP addresses into the console
getIPs(function(ip){console.log(ip);});

因为Firefox和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。

解决办法

那我们有没有办法继续装逼呢？答案是肯定的。我们可以关闭WebRTC。

Chrome

安装插件 https://chrome.google.com/webstore/detail/webrtc-block/nphkkbaidamjmhfanlpblblcadhfbkdm?hl=en

无法下载的一定是你上网姿势不科学。

Firefox

用 media.peerconnection.enabled 禁用。BTW，方法网上看到了，电脑没装Firefox，所以你们自己摸索吧。

参考资料

来自http://www.giuem.com/js-get-ip/