How can I fix slow SMB file transfers on macOS 10.11.5?

How can I fix slow SMB file transfers on macOS 10.11.5?

Purpose

For security reasons, Mac OS X 10.11.5 enables SMB client signing by default, thus impacting the transfer speed of SMB files. If you want to perform SMB file transfers over LAN (we do not recommend you to perform SMB file transfers via the Internet for security purposes), follow the instructions below to disable SMB client signing from the client end via /etc/nsmb.conf file.

Resolution

  1. Go to Applications > Utilities to open Terminal.
  2. Create an empty file /etc/nsmb.conf:
  3. sudo touch /etc/nsmb.conf
  4. Open /etc/nsmb.conf with vi:
  5. sudo vi /etc/nsmb.conf
  6. Modify the value of signing_required by entering the following:
  7. [default]
    signing_required=no
  8. Press the Esc key and then type"ZZ" to save the changes and exit vi.
  9. Reboot your MAC.