To some, the nature of the Samba security mode is obvious, but entirely wrong all the same. It is assumed that security = server means that Samba will act as a server. Not so! This setting means that Samba will try to use another SMB server as its source for user authentication alone.

Samba is a server regardless of which security mode is chosen. When Samba is used outside of a domain security context, it is best to leave the security mode at the default setting. By default Samba-3 uses user-mode security.