Here are the names and port numbers to use for the U-M Kerberos servers provided and maintained by ITS:
Realm:
UMICH.EDU
Kerberos Servers:
kerberos-1.umich.edu Port: 88
kerberos-2.umich.edu Port: 88
kerberos-3.umich.edu Port: 88
Kerberos Admin Server:
kerberos-admin.umich.edu Port: 749