Use an Existing MIT KDC
To use an existing MIT KDC for the cluster, you must prepare the following:
Ambari Server and cluster hosts have network access to both the KDC and KDC admin hosts.
KDC administrative credentials are on-hand.
You will be prompted to enter the KDC Admin Account credentials during the Kerberos setup so that Ambari can contact the KDC and perform the necessary principal and keytab generation. By default, Ambari will not retain the KDC credentials unless you have configured Ambari for encrypted passwords.