When you install the Informatica services with Kerberos authentication, you can set the Service Principal Level option to specify whether nodes and services can share service principal names and keytab files. If the domain does not require a high level of security, you can use one SPN and keytab file for the node and all the service processes on the node. If the domain requires a high level of security, create a unique SPN and keytab file for each node and each process on the node.