Each KDC (including the master) needs a keytab to decrypt tickets. Ideally, you should extract each keytab locally on its own KDC. If this is not feasible, you should use an encrypted session to send them across the network. To extract a keytab on a KDC called kerberos.mit.edu, you would execute the following command:
kadmin: ktadd host/kerberos.mit.edu kadmin: Entry for principal host/kerberos.mit.edu@ATHENA.MIT.EDU with kvno 1, encryption type DES-CBC-CRC added to keytab WRFILE:/etc/krb5.keytab. kadmin:
Note that the principal must exist in the Kerberos database in order to extract the keytab.