andrijeski/index.html

## index.html
<!DOCTYPE html>
<html>
<body>
  <head><script src="ipcheck.js"></script></head>
<body>
Your network IP is: <h1 id=list>-</h1>
</body>
</html>

## ipcheck.js
// NOTE: window.RTCPeerConnection is "not a constructor" in FF22/23
var RTCPeerConnection = /*window.RTCPeerConnection ||*/ window.webkitRTCPeerConnection || window.mozRTCPeerConnection;

if (RTCPeerConnection) (function () {
    var rtc = new RTCPeerConnection({iceServers:[]});
    if (1 || window.mozRTCPeerConnection) {      // FF [and now Chrome!] needs a channel/stream to proceed
        rtc.createDataChannel('', {reliable:false});
    };

    rtc.onicecandidate = function (evt) {
        // convert the candidate to SDP so we can run it through our general parser
        // see https://twitter.com/lancestout/status/525796175425720320 for details
        if (evt.candidate) grepSDP("a="+evt.candidate.candidate);
    };
    rtc.createOffer(function (offerDesc) {
        grepSDP(offerDesc.sdp);
        rtc.setLocalDescription(offerDesc);
    }, function (e) { console.warn("offer failed", e); });


    var addrs = Object.create(null);
    addrs["0.0.0.0"] = false;
    function updateDisplay(newAddr) {
        if (newAddr in addrs) return;
        else addrs[newAddr] = true;
        var displayAddrs = Object.keys(addrs).filter(function (k) { return addrs[k]; });
        document.getElementById('list').textContent = displayAddrs.join(" or perhaps ") || "n/a";
    }

    function grepSDP(sdp) {
        var hosts = [];
        sdp.split('\r\n').forEach(function (line) { // c.f. http://tools.ietf.org/html/rfc4566#page-39
            if (~line.indexOf("a=candidate")) {     // http://tools.ietf.org/html/rfc4566#section-5.13
                var parts = line.split(' '),        // http://tools.ietf.org/html/rfc5245#section-15.1
                    addr = parts[4],
                    type = parts[7];
                if (type === 'host') updateDisplay(addr);
            } else if (~line.indexOf("c=")) {       // http://tools.ietf.org/html/rfc4566#section-5.7
                var parts = line.split(' '),
                    addr = parts[2];
                updateDisplay(addr);
            }
        });
    }
})(); else {
    document.getElementById('list').nextSibling.textContent = "In Chrome and Firefox your IP should display automatically.";
};
	<!DOCTYPE html>
	<html>
	<body>
	<head><script src="ipcheck.js"></script></head>
	<body>
	Your network IP is: <h1 id=list>-</h1>
	</body>
	</html>
	// NOTE: window.RTCPeerConnection is "not a constructor" in FF22/23
	var RTCPeerConnection = /window.RTCPeerConnection \|\|/ window.webkitRTCPeerConnection \|\| window.mozRTCPeerConnection;

	if (RTCPeerConnection) (function () {
	var rtc = new RTCPeerConnection({iceServers:[]});
	if (1 \|\| window.mozRTCPeerConnection) { // FF [and now Chrome!] needs a channel/stream to proceed
	rtc.createDataChannel('', {reliable:false});
	};

	rtc.onicecandidate = function (evt) {
	// convert the candidate to SDP so we can run it through our general parser
	// see https://twitter.com/lancestout/status/525796175425720320 for details
	if (evt.candidate) grepSDP("a="+evt.candidate.candidate);
	};
	rtc.createOffer(function (offerDesc) {
	grepSDP(offerDesc.sdp);
	rtc.setLocalDescription(offerDesc);
	}, function (e) { console.warn("offer failed", e); });


	var addrs = Object.create(null);
	addrs["0.0.0.0"] = false;
	function updateDisplay(newAddr) {
	if (newAddr in addrs) return;
	else addrs[newAddr] = true;
	var displayAddrs = Object.keys(addrs).filter(function (k) { return addrs[k]; });
	document.getElementById('list').textContent = displayAddrs.join(" or perhaps ") \|\| "n/a";
	}

	function grepSDP(sdp) {
	var hosts = [];
	sdp.split('\r\n').forEach(function (line) { // c.f. http://tools.ietf.org/html/rfc4566#page-39
	if (~line.indexOf("a=candidate")) { // http://tools.ietf.org/html/rfc4566#section-5.13
	var parts = line.split(' '), // http://tools.ietf.org/html/rfc5245#section-15.1
	addr = parts[4],
	type = parts[7];
	if (type === 'host') updateDisplay(addr);
	} else if (~line.indexOf("c=")) { // http://tools.ietf.org/html/rfc4566#section-5.7
	var parts = line.split(' '),
	addr = parts[2];
	updateDisplay(addr);
	}
	});
	}
	})(); else {
	document.getElementById('list').nextSibling.textContent = "In Chrome and Firefox your IP should display automatically.";
	};