Skip to main content

CIFS, SMB1, SMB2, SMB3 Protocols

Definition of CIFS, SMB2, and SMB3 protocols.  Information about the deactivation of SMB1 protocol and system implications.

This article applies to: Shared File Services


Shared File Services supports the SMB2 and SMB3 protocols. 

The SMB1 protocol was removed effective 4/29/2018 from the Cornell Active Directory (AD) Domain Controllers and the \\files.cornell.edu DFS servers used by SFS. 

SMB1 is not supported.

Lack of SMB1 may impact older systems that require the protocol, including:

  • Windows XP
  • Windows Server 2003
  • Network printers
  • Other network-connected devices with embedded systems using SMB1
  • Linux systems running outdated versions of Samba.


Impact may include the inability to access network shares, process GPOs, browsing the "Network," printers being unable to scan or save to a network share, or similar actions.

MacOS users who map to Windows shares via cifs://files.cornell.edu/OU/SHARE will experience failures.  This happens because the cifs prefix forces a SMB1 connection from MacOS, which is no longer supported.

  • Bad:        cifs://files.cornell.edu/OU/SHARE
  • Good:      smb://files.cornell.edu/OU/SHARE


More background on this issue:

For additional information regarding the SMB protocol see Wikipedia.

Other Schools and Departments are utilizing Shared File Services’ DFS namespace to access departmental file servers which are not managed by SFS. These departmental shares may not support features such as snapshots.
SFS documentation uses the abbreviation “CIFS” over “SMB” as it is  more commonly understood, even if technically incorrect.

Was this page helpful?

Your feedback helps improve the site.

Comments?