At least in the installation there are built-in assumptions about IPv4. It determines the reverse zone by using the current IPv4 address only. I'm pretty sure it would blow up on an IPv6-only network.
Changing the summary since there are IPv4-specific functions all over the place, not just DNS installation. Notably socket.gethostbyname() and asking for DNS_T_A records only when verifying FQDN.
Status update - the IPA server now installs fine on an IPv6 machine but is not operational due to https://bugzilla.redhat.com/show_bug.cgi?id=660332
A partial fix that touches just the installer has been commited in ee4d273
master: bb56285
Metadata Update from @rcritten: - Issue assigned to jhrozek - Issue set to the milestone: FreeIPA 2.0 - 2011/01 (cleanup)
Login to comment on this ticket.