[Samba] Samba4 server not visible browsing network listed machines

[Daniele Manfredi]

Hi,
I have setted a AD-DC controller with Ubuntu Server 14.04 LTS and Samba 4.
When I browse my network using a Windows client (XP, 7 , 8 and10) I 
can't see my new server in the listed machines.
I can see all  Windows and Linux samba3 machines: only if I call the 
Samba4 server by ip address I can see all my shared folders on it.
Is there a way to make it visible by Windows clients?

Thanks in advance for your help.
Daniele