At IU, how do I ensure interoperability between Samba and Windows computers?

UITS does not support the LAN Manager (LM) and NTLMv1 authentication protocols on the Indiana University Active Directory. Nearly all Windows computers on the IU network are configured to use only NTLMv2. Windows computers on ADS received a policy configuring them to accept only NTLMv2; owners of Windows computers not joined to ADS can change their settings on their own, either with an executable available on IUware, or manually through certain console or registry settings.

This affects how Windows computers on the IU network access Samba file or printer shares on Unix, Linux, and BSD servers. Only recent versions of Samba can understand the NTLMv2 protocol, and by default that ability is disabled in those versions. Therefore, if you administer a server running Samba, you may see a problem with Windows clients unless you take action to avoid it.

While it's impossible to cover every configuration across every version of Unix, Linux, or BSD, the way to avoid the problem can be generalized as follows:

  • The server administrator must be running a version of Samba capable of handling NTLMv2 securely. UITS recommends versions currently supported by the Samba team.
  • The smb.conf must include a line in the Global Settings section, labeled [global], that reads:
     client ntlmv2 auth = yes

At Indiana University, for personal or departmental Linux or Unix systems support, see At IU, how do I get support for Linux or Unix?

This is document atvt in the Knowledge Base.
Last modified on 2017-05-16 12:14:50.

  • Fill out this form to submit your issue to the UITS Support Center.
  • Please note that you must be affiliated with Indiana University to receive support.
  • All fields are required.

Please provide your IU email address. If you currently have a problem receiving email at your IU account, enter an alternate email address.

  • Fill out this form to submit your comment to the IU Knowledge Base.
  • If you are affiliated with Indiana University and need help with a computing problem, please use the I need help with a computing problem section above, or contact your campus Support Center.

Please provide your IU email address. If you currently have a problem receiving email at your IU account, enter an alternate email address.