Microsoft KB Archive/170642

{|
 * width="100%"|

FIX: Call to WSAIoctl with SIO_GET_INTERFACE_LIST Option Fails

 * }

Q170642

-

The information in this article applies to:


 * Microsoft Win32 Application Programming Interface (API), included with:
 * Microsoft Windows NT Server version 4.0
 * Microsoft Windows NT Workstation version 4.0

-

SYMPTOMS
When the SIO_GET_INTERFACE_LIST option is used in a call to WSAIoctl, the API returns WSAENOPROTOOPT or sometimes causes an access violation in wshtcpip.dll. As a result of this behavior, you cannot get a descriptive list of the network interfaces on your machine.

STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

This problem was corrected in Windows NT Service Pack 4.0.

MORE INFORMATION
Winsock2 has new functionality that enables you to obtain information about the network interfaces supported by your machine. Some of the information returned for each interface is:

IP address Subnet Mask Broadcast Address, etc.

You should have been able to get this information by making a call to the WSAIoctl API with the SIO_GET_INTERFACE_LIST option. However, due to the bug mentioned above, the API fails with error WSAENOPROTOOPT or sometimes causes an access violation in wshtcpip.dll.