JSI Tip 1322. SP5 allows you to disable the source routing feature of TCP/IP.

Starting with Service Pack 5, Windows NT 4.0 allows you to disable the source routing feature of TCP/IP.

Use Regedt32 to navigate to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

On the Edit menu, Add Value name DisableIPSourceRouting, as a type REG_DWORD, and set the data value to 1, which disables source routing. A 0, the default, enables source routing.