How to Disable the Gratuitous ARP Function

• Microsoft Windows NT Workstation versions 4.0, 4.0 SP1, 4.0 SP2, 4.0 SP3, 4.0 SP4
• Microsoft Windows NT Server versions 4.0, 4.0 SP1, 4.0 SP2, 4.0 SP3, 4.0 SP4
• Microsoft Windows NT Server, Enterprise Edition versions 4.0, 4.0 SP4
• Microsoft Windows 2000 Professional
• Microsoft Windows 2000 Server
• Microsoft Windows 2000 Advanced Server

SYMPTOMS

When a Windows NT-based computer starts, a packet is broadcast on the network containing the computer's TCP/IP address to prevent the use of duplicate addresses on the same network. This is called a gratuitous Address Resolution Protocol (ARP) packet. Routers and other network hardware may cache routing information gained from multiple gratuitous ARP packets. For both performance and maintenance reasons, it is possible to disable this feature in Windows NT.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was first corrected in Windows NT 4.0 Service Pack 5.

MORE INFORMATION

To disable gratuitous ARPs after applying this hotfix:

1. Click Start, click Run, type regedt32, and then click OK.



2. On the Windows menu, click HKEY_LOCAL_ MACHINE on Local Machine.



3. Click the \System\CurrentControlSet\Services\TcpIp\Parameters folder.



4. Double-click the ArpRetryCount value, type 0, and then click OK.



5. Quit Registry Editor, and then restart the computer.

Q199773 Behavior of Gratuitous ARP in Windows NT 4.0

Additional query words:

Keywords : kbenv kbnetwork ntsp kbbug4.00 nt4sp5fix
Version : WINDOWS:2000; winnt:4.0,4.0 SP1,4.0 SP2,4.0 SP3,4.0 SP4
Platform : WINDOWS winnt
Issue type : kbbug