Configure SMB use of Netbios

25 May 2003 by Snakefoot | Comment » | Trackback Off
With Windows 2000 the first move away from Netbios was made. Instead DNS should be used for name resolution and SMB Direct Hosting at TCPIP port 445 for requests instead of port 139.

By standard both port 139 and 445 is open to get the highest degree of compatibility. A client will try to request on both ports and continue the communication on the port which responds first.

To disable SMB use of Netbios port 139 (Forces use of port 445):
  1. On the Start menu, point to Settings, and then click Network and Dial-up Connections
  2. Right-click Internet facing connection, and then click Properties.
  3. Select Internet Protocol TCP/IP and select Properties
  4. Click Advanced and select the WINS tab
  5. Tick Disable NetBIOS over TCP/IP and click Ok
To disable SMB use of port 445 with this DWORD (Forces use of port 139):

[HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \NetBT \Parameters]
SMBDeviceEnabled = 0

To disable SMB use of port 139 and 445 (Disables nbt.sys driver):
  1. Right-click My Computer on the desktop, and then click Manage.
  2. Expand System Tools, and then select Device Manager.
  3. Right-click Device Manager, point to View, and then click Show hidden devices.
  4. Expand Non-Plug and Play Drivers.
  5. Right-click NetBios over Tcpip, and then click Disable.
To disable SMB completely:
  1. On the Start menu, point to Settings, and then click Network and Dial-up Connections
  2. Right-click Internet facing connection, and then click Properties.
  3. Select Client for Microsoft Networks, and then click Uninstall.
  4. Follow the uninstall steps.
  5. Select File and Printer Sharing for Microsoft Networks, and then click Uninstall.
  6. Follow the uninstall steps.
Related Configure SMB signing in WinNT+

More Info MS KB Q204279
More Info MS KB Q253959

Credits ntsecurity.nu

Updated: 17 May 2007

Leave a comment


NB! Use the Forum for computer help and off-topic questions.

You can use these tags: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <code> <em> <i> <strike> <strong>