Red Hat Enterprise IPA makes use of the following ports:
TCP
80, 443, 8080: HTTP/HTTPS
389, 636: LDAP/LDAPS
88, 464: Kerberos
UDP
88, 464: Kerberos
123: NTP
Ensure that these ports are available; that is, that they are not assigned to another service. If these ports are not available, IPA will not function correctly.
Refer to Bug #450941 in the Known Issues section of the Red Hat Enterprise IPA Release Notes for more information.