Certificate issue with management UI

Hopefully this is something obvious that I am missing. We just installed our Isilon A400 with 4 nodes. I successfully installed a certificate for the management portal in order not to get the "untrusted site" warnings. I registered the cert with our FQDN for the management UI however the URL also changes to an IP address and therefore the cert gives me the warning.   I'm thinking I have to create a SAN Certificate entry for each IP address?