Kerberos packages may be installed by default, but make sure that the appropriate packages are installed for the Kerberos server or client being configured.
To install packages for a Kerberos server:
# yum install krb5-server krb5-libs krb5-auth-dialog
To install packages for a Kerberos client:
# yum install krb5-workstation krb5-libs krb5-auth-dialog
If the Red Hat Enterprise Linux system will use Kerberos as part of single sign-on with smart cards, then also install the required PKI/OpenSSL package:
# yum install krb5-pkinit-openssl