small update as I've managed to narrow things down.
the following will NOT work
[realms]kdc=server1kdc=server2kdc=server3kdc=server4master_kdc=server1master_kdc=server2master_kdc=server3master_kdc=server4
when server1 and server2 are down on the network. server3 and server4 are up and
functional
but the following WILL work
[realms]kdc=server1kdc=server2kdc=server3kdc=server4master_kdc=server1#
master_kdc=server2master_kdc=server3master_kdc=server4
So the problem seems to be with having more than one non-functioning master_kdc ??! One
seems to be ok but more than one and kinit chokes.