samba 3.4 ADS support broken on ipv6 networks ?

[Pim Zandbergen]

Our Windows 2003 domain controllers and Samba member servers
support both ipv4 and ipv6. Our DNS server resolves hostnames
both to ipv4 and ipv6 addresses.

Recently, this turned out to be a problem when within a regular
Fedora 11 update, samba 3.2 was replaced with samba 3.4.
samba-3.4.2-0.42.fc11.i586 to be exact.

Everything Active Directory related stopped working and I had
to stop winbind because it started to eat all open file resources.

A quick look with wireshark shows that the Samba 3.4 member server
tries to make an ipv6 LDAP connection to the Windows 2003 DC.

Now Windows 2003 does support ipv6, but its AD LDAP service
does not. Samba, like any other app should fall back to ipv4,
but apparantly does not.

There more evidence to my theory because

    net ads testjoin -S dc


  fails with

2009/11/04 14:29:47,  0] utils/net_ads.c:279(ads_startup_int)
   ads_connect: No logon servers
Join to domain is not valid: No logon servers

and

    net ads testjoin -S dc.ipv4

succeeds.

Here, "dc" resolves to both ipv4 and ipv6 addresses,
and "dc.ipv4" resolves to an ipv4 address only.

Has anyone else seen this problem?
I have seen no mention of this problem on either Samba or Fedora
mailinglists, nor in bugzilla.redhat.com

Thanks,
Pim