[Samba] Samba4 machine fails to join in samba3 domain

[Julien TEHERY]

Louis is right, you should upgrade, but, in the meantime, try adding 
'ntlm auth = yes' to your smb.conf, see if that helps.
>
> Also try running the following commands:
>
> net getlocalsid
>
> net getdomainsid
>
> Rowland
>
Yes they should upgrade, I totally agree. I've allready migrated samba3 
domain to samba4 domain , but in this case the samba4 one is only a 
fileserver that was joined in a microsoft/AD domain. People from the 
samba3 domain used to access their home on it through bidirectionnal 
approbation approval between the microsoft domain and samba3 domain.
Now they have to break this approval to upgrade their forest functionnal 
level. That's why we try to integrate this samba4 fileserver into the 
old samba3 domain, so that users can still have access to their homes.

I tried with the ntlm_auth option whitout success.

I won't bother your with samba3 problems, but can somebody explain what 
root's SID has to deal with the "net rpc join" command?
I precise this SID does exists in the samba3 (target) domain and the SID 
is the same as shown in my first email.