[Samba] error message during attempting to join the domain of the samba server

[nikos sarantopoulos]

hello

when i prepare the samba 4.7 server i make the samba-tool domain provision
i add the domain and host to /etc/hosts file

but when i run the server and i attempt to join from windows 7 machine i
get :

the following error occurred attempting to join the domain "nsarnet"
the specified server cannot perform the requested operation

am i doing something wrong?

thank you