[Samba] Net Join Samba 4 to Samba 3 PDC?

[D J]

Hi,

I have a retro LAN running things like Sun SPARCclassics, Ultra1s, Win98
and WinXP. I decided to standardize most of the Sun boxes on the latest
versions of OpenBSD that support their architectures (5.9 for Sun4c &
Sun4m, 7.4 for Sun4u). I have a Debian 7 server with RAIDs to store all the
packages, configs, games, etc. I like to use Samba to transfer the files
back and forth between the various systems.

I have always had all the smbd authenticate to a single smbd (on SERVER3)
to simplify password management. But only Samba 4 is available on OpenBSD
7.4, and it won't authenticate against the Samba 3 on the Debian 7 server.
Is there a way to get this to work?

Here are the configs, minus all the parameters that are (I hope) irrelevant.

SERVER3 "The authentication server" = Debian 7 "Wheezy" Samba-3.6.6-6
NOTE: This config has been working great for many years, I don't want to
screw it up.
[global]
 workgroup = WORKGROUP1
 netbios name = SERVER3
 server string = Samba Server %v on %h
 map to guest = Bad User
 obey pam restrictions = Yes
 pam password change = Yes
 passwd program = /usr/bin/passwd %u
 passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:*
%n\n *password\supdated\ssuccessfully* .
 unix password sync = Yes
 lanman auth = Yes
 client NTLMv2 auth = No
 client lanman auth = Yes
 client plaintext auth = Yes
 name resolve order = lmhosts host wins bcast
 logon script = %U.bat
 logon path = \export\logon
 domain logons = Yes
 os level = 33
 preferred master = Yes
 domain master = Yes
 wins support = Yes
 usershare allow guests = Yes
 idmap config * : range =
 idmap config * : backend = tdb

SUN6 "The authentication client" = OpenBSD-SPARC64 7.4 Samba-4.19.0v0
NOTE: I've been experimenting with different options here, this is just
what is current.
[global]
 workgroup = WORKGROUP1
 netbios name = SUN6
 server string = Samba Server %v on %h
 server role = MEMBER
 password server = SERVER3
 hosts allow = 192.168.0. 127.
 dns proxy = no
[sd2a]
 comment = sun6 filesystem share
 path = /
 valid users = root
 admin users = root
 read only = no
 browsable = yes


To configure the various samba servers to all authenticate to SERVER3 I
have always used this method:

SERVER3# useradd -u 1006 -g 1006 -c "SUN6 Samba" -s /sbin/nologin -d
/dev/null SUN6$

SERVER3# smbpasswd -a -m SUN6$

SUN6# smbpasswd -j WORKGROUP1 -U root

SUN6# net join -S SERVER3 -U root
===But instead of joining, I get the following two lines of output===
Password for [WORKGROUP1\root]:
Failed to join domain: failed to lookup DC info for domain 'WORKGROUP1'
over rpc: The transport connection is now disconnected.


These are configs from some of the other Sun boxes running Samba 3 that has
worked for a long time:
SUN1
[global]
 workgroup = WORKGROUP1
 netbios name = SUN1
 server string = Samba Server %v on %h
 security = SERVER
 encrypt passwords = true
 password server = SERVER3
 restrict anonymous = Yes
 name resolve order = host lmhosts wins bcast
 preferred master = False
 local master = No
 domain master = False
 hide dot files = No
 wide links = No
 follow symlinks = No
[sda1]
 comment = SUN1 filesystem share
 path = /
 username = root
 read only = No

SUN4
[global]
 workgroup = WORKGROUP1
 netbios name = SUN4
 server string = Samba Server %v on %h
 security = SERVER
 encrypt passwords = Yes
 password server = SERVER3
 name resolve order = host lmhosts wins bcast
 preferred master = False
 local master = No
 domain master = False
 mangle case = Yes
 hide dot files = No
 wide links = No
 follow symlinks = No
[sd0a]
 comment = SUN4 filesystem share
 path = /
 username = root
 read only = No

I've been searching for the answer, but I don't think I'm using the correct
search terms because I've not found an aanswer.  Please note that
rebuilding SERVER3 to the latest and greatest OS and Samba is not an option
at this time.  Any help getting this working would be greatly appreciated!

Thanks,
DJ