With iprop, this is what I usually do:
On the master:
add iprop/<slave-hostname>@REALM to /var/heimdal/slaves
On the slave:
ktutil get iprop/`hostname`
copy the master key from the master
ipropd-slave <master-hostname>
To test you have to change your krb5.conf (or DNS - whatever) to point
to the slave.
/Johan