This simple JS script, using an external site, allows you to prevent certain IPs from viewing an experiment for Optimizely Gold clients.

Redcross.js

<script>
var myip; //declares variable to store IP address

var doNotTest = ["012.345.678.9"]; //creates an array to store IPs, separated by a comma, that shouldn't see experiment

</script>

<script type="text/javascript" src="http://l2.io/ip.js?var=myip"></script>

<script>
    for (ip in doNotTest) { //runs through each IP address in doNotTest
    
	    if (myip != doNotTest[ip]) { //if this condition is met, experiment will run
		    
	    }
};
</script>