http://web.mit.edu/Kerberos/krb5-1.5/krb5-1.5.1/doc/krb5-install/UNIX-Application-Servers.html#UNIX%20Application%20Servers

Click "The Keytab File"

	"The Keytab File

	All Kerberos server machines need a keytab file, called
	/etc/krb5.keytab, to authenticate to the KDC. ..."

As a newbie, the phrase "Kerberos server machines" in this context
was confusing.  Perhaps it just needs to say "Kerberos application
server machines"...