For additional reference, recent Samba known cybersecurity vulnerabilities report (apply to Samba 3 & 4) indicate a change in default setting for "client ipc signing" as well as the global conf options newly introduced to keep compatibility:
SMB client connections for IPC traffic are not integrity protected https://www.samba.org/samba/security/CVE-2016-2115.html As highlighted by John, the only possible settings are "auto", "mandatory" and "disabled"... ** CVE added: http://www.cve.mitre.org/cgi- bin/cvename.cgi?name=2016-2115 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1572122 Title: Samba upgrade to 3.6.25-0ubuntu0.12.04.2 break domain authentication To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/samba/+bug/1572122/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs