If this environment is using Kerberos then please verify to see if SPN is set using only the FQDN. If that is the case then make sure that you also register the SPN by using the NetBIOS name of the server that is running IIS to avoid being prompted for your user credentials. The 30-minutes time-out occurs because of the way that Internet Explorer caches Domain Name System (DNS) information.
Have more questions? Submit a request