Advanced Windows Networking Using Internet Protocol

Windows Networking, the subsystem that lets you share files and printers between computers running the various versions of Windows, uses Internet Protocol to attach to the physical networking components, in it’s default state. It will use alternate network transports, for those with special needs.

Starting with Windows 98, and in every version of Windows since then, Windows Networking has used NetBIOS Over TCP (NetBT) as an interface between Internet Protocol and the various applications. Windows 2000 and XP, however, will run Windows Networking without the involvement of NetBT. This is known as direct hosting of SMB (Server Message Blocks).

To remain compatible with the older versions of Windows, a Windows Networking client, under Windows 2000 or Windows XP, can uset either direct hosted SMBs or NetBT. If direct hosted SMBs are available, on a given server, a Windows Networking client will bypass NetBT and use direct hosted SMBs, when communicating with that server.

This dual compatibility, allowing Windows 2000 / XP clients to communicate with computers running other editions of Windows, is not without cost. Trying for two communications channels, when establishing a connection with any server, increases program complexity and network traffic. In some cases, it may increase latency.

If your LAN

  • Has a domain.
  • Has computers running only Windows 2000, Windows 2002 (aka Windows XP), and Windows 2003 (aka Server 2003).
  • Uses DNS, properly setup, for name resolution.

then you may wish to disable NetBT, and use direct hosted SMBs.

In TCP/IP Properties, Advanced, WINS, select Disable NetBIOS Over TCP/IP. Alternately, if you have the Default NetBIOS setting selected (instead of “Disable” or “Enable”) on your client computers, and you have a DHCP server (not a NAT router with DHCP), you can disable NetBT from a DHCP server setting.

If you use direct hosted SMBs, whether alternately or exclusively, be aware of the security implications.

  • NetBT uses TCP and UDP ports 137 – 139.
  • Direct hosted SMBs use TCP port 445.

Be sure to adjust the settings on the firewall, appropriately.

One Response to “Advanced Windows Networking Using Internet Protocol”

  1. evilbitz Says:

    Cool post!

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