Sorry for not replying, had other issues to deal with.
I have managed to connect to domain with my computers (managed on win7, win10, osx 10.12). Nethserver is installed and has local ip 192.168.21.7. AD has local ip 192.168.21.8.
Another problem arised. I have user named dtc and I want to reach samba shared folder named public with no success. This is a win7 computer. I have tried several ideas:
1.) through Run command trying to reach 192.168.21.7 - I can see Public share, but I cannot access it with dtc account and password.
2.) through net use command by assigning to a network drive - says it is access denied.
3.) through windows control panel by saving the credentials and then by mapping the drive - same story, access denied.
Then I tried to setup the Shared Folders under Management in NethServer.
1.) made ACL with user dtc in it - does nothing.
2.) made group named Public with dtc in it, and then make that group the owner of the Public share - nothing changed.
3.) returned to Domain Users as owner of the group - nothing also.
4.) gave permission to Guest users (read only and later rw) - dtc user still couldn't access the shared folder, but with Guest I could.
Now I don't know what else to do. Is there some permissions problem I need to take care first?
Also, one NOTE: every time I submit something in settings in Shared Folders in Management I got this error message, but it seems Nethserver to accept the changes: S20nethserver-ibays-set-permissions #2 (exit status 256).
Another NOTE: I managed to reach Shared folder in only one try: when I was connected with roaming profile on AD, and only when I mapped the shared folder through net use command, everything else failed.
What I need is that my user dtc can reach that damned public folder through smb.
picture of shared folders settings: