Samba 3 should be able to join a Longhorn based AD domain over IPv6. It cannot at present.
Test by installing Longhorn server. Configure Longhorn with a global IPv6 address. Then add the AD domain controller and DNS roles.
Configure the Samba client with a global IPv6 address. Configure Samba3 as normal for an AD client.
Next attempt to join the Longhorn domain using the Samba3 net command as normal. Samba 3 should join the domain over IPv6 in preference to IPv4, if IPv6 DNS records (AAAA) exist for the domain controller and if IPv6 transport is available. If either of these are not true then Samba3 should fall back to joining the domain over IPv4. This process should be invisible to the user.
Let me know if you need help testing or any further information.
once bug 10030 is being fixed can you try again with Samba 4 and see how that works for you?
(In reply to comment #1)
Will do. As it turns out we did get Samba 3 to join AD domains over IPv6. Thanks for chasing updating this bug.
comment #2 says it works now.