código para obtener la ip del navegador y mostrarlo

<script type="text/javascript">
    var ip = '';
    window.RTCPeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection;
    var pc = new RTCPeerConnection({iceServers:[]}), noop = function(){};
    pc.createDataChannel("");
    pc.createOffer(pc.setLocalDescription.bind(pc), noop);
    pc.onicecandidate = function(ice){
        if(!ice || !ice.candidate || !ice.candidate.candidate) return;
        ip = /([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];
        pc.onicecandidate = noop;
        document.getElementById("ip").innerHTML = ip;