[Samba] Problem joining Samba 4 to Samba 3 PDC

[Sonic]

On Tue, Nov 1, 2016 at 12:03 PM, Gaiseric Vandal via samba
<samba at lists.samba.org> wrote:
> My guess is that the samba 3.6.x machine  is not patched for BADLOCK
> vulnerabilities and the  4.5.x machine is.

Though it was odd that a patched Win7 system works but not a Samba 4 system.

However, after placing these statements in the smb.conf Samba 4 could
join the old Samba 3 domain!
============================
client ipc signing = No
client signing = No
server signing = No
============================
It's probably the 'client signing = No' that solved the issue but I
haven't yet verified.

Chris