BCASTADDR Functionality Not Included in Windows NT

ID: Q117375

3.10 WINDOWS kbnetwork

The information in this article applies to:


LAN Manager versions 2.1 and 2.2 and Windows for Workgroups version 3.11 allow an entry in the PROTOCOL.INI file, [tcpip] section for BCASTADDR. This functionality is not included in Windows NT or Windows NT Advanced Server.


In LAN Manager and Windows for Workgroups, this TCP/IP parameter forces the IP address used to broadcast name requests. It allows an address of or to be used for this purpose.

The following Windows NT Registry entry affects the broadcast address, but only the last two octets:

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\<adapter name#>
      \parameters \tcpip

   BroadcastType    REG_DWORD
      This value can be 0 or 1  (1 by default)

Assume a workstation has a TCP/IP address of and a subnet mask of The workstation address is ANDed with the subnet mask to find the first two octets of 130.24. When BroadcastType is set to 1, the broadcast address becomes When BroadcastType is set to 0, the broadcast address becomes


Microsoft LAN Manager "Installation and Configuration Guide," version 2.2,

   pages 195 - 196

Microsoft LAN Manager "Installation and Configuration Guide," version 2.1,
   pages 181 - 182

Microsoft Windows for Workgroups Resource Kit, "Addendum for Operating
   System Version 3.11," pages 6 - 19, 6 - 20

Microsoft Windows NT Resource Kit, "Windows NT Resource Guide," Volume 1,
   page 486

Additional reference words: prodnt wfw wfwg 3.10 KBCategory: kbnetwork KBSubcategory: ntprotocol
Keywords          : ntprotocol 
Version           : 3.10
Platform          : WINDOWS

Last Reviewed: September 10, 1996