You can create an IP cluster in the Management section.

In the above example the customer has an IP of 123.45.67.89 and a second IP of 13.14.15.16   

If using a hostname it would be for example xyz.com#10;xyz.com#20;

#10 Denoting this IP is the Priority 1 status

#20 Denoting this IP is the Priority 2 status etc.