GetIfEntry2 function (netioapi.h)

The GetIfEntry2 function retrieves information for the specified interface on the local computer.

Syntax

IPHLPAPI_DLL_LINKAGE _NETIOAPI_SUCCESS_ NETIOAPI_API GetIfEntry2(
  PMIB_IF_ROW2 Row
);

Parameters

Row

A pointer to a MIB_IF_ROW2 structure that, on successful return, receives information for an interface on the local computer. On input, the InterfaceLuid or the InterfaceIndex member of the MIB_IF_ROW2 must be set to the interface for which to retrieve information.

Return value

If the function succeeds, the return value is NO_ERROR.

If the function fails, the return value is one of the following error codes.

Return code Description
ERROR_FILE_NOT_FOUND
The system cannot find the file specified. This error is returned if the network interface LUID or interface index specified by the InterfaceLuid or InterfaceIndex member of the MIB_IF_ROW2 pointed to by the Row parameter was not a value on the local machine.
ERROR_INVALID_PARAMETER
An invalid parameter was passed to the function. This error is returned if a NULL parameter is passed in the Row parameter. This error is also returned if the both the InterfaceLuid and InterfaceIndex member of the MIB_IF_ROW2 pointed to by the Row parameter are unspecified.
Other
Use the FormatMessage function to obtain the message string for the returned error.

Remarks

The GetIfEntry2 function is defined on Windows Vista and later.

On input, at least one of the following members in the MIB_IF_ROW2 structure passed in the Row parameter must be initialized: InterfaceLuid or InterfaceIndex.

The fields are used in the order listed above. So if the InterfaceLuid is specified, then this member is used to determine the interface. If no value was set for the InterfaceLuid member (the value of this member was set to zero), then the InterfaceIndex member is next used to determine the interface.

On output, the remaining fields of the MIB_IF_ROW2 structure pointed to by the Row parameter are filled in.

Note that the Netioapi.h header file is automatically included in Iphlpapi.h header file, and should never be used directly.

Examples

The following example retrieves a interface entry specified on the command line and prints some values from the retrieved MIB_IF_ROW2 structure.

#ifndef UNICODE
#define UNICODE
#endif

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif

#include <Windows.h>

#include <winsock2.h>
#include <ws2tcpip.h>
#include <iphlpapi.h>

#include <objbase.h>
#include <wtypes.h>
#include <stdio.h>
#include <stdlib.h>

// Need to link with Iphlpapi.lib
#pragma comment(lib, "iphlpapi.lib")

// Need to link with Ole32.lib to print GUID
#pragma comment(lib, "ole32.lib")

void PrintIfEntry2(PMIB_IF_ROW2 pifRow);

int __cdecl wmain(int argc, WCHAR ** argv)
{

    // Declare and initialize variables

    ULONG retVal = 0;
    ULONG ifIndex;

    MIB_IF_ROW2 ifRow;

    // Make sure the ifRow is zeroed out
    SecureZeroMemory((PVOID) &ifRow, sizeof(MIB_IF_ROW2) );

    // Zero out the MIB_IF_ROW2 struct

    // Validate the parameters
    if (argc < 2) {
        wprintf(L"usage: %s <InterfaceIndex>\n", argv[0]);
        wprintf(L"   Gets the Interface Entry for an interface Index,\n");
        wprintf(L"Example to get the interface at interface index=6\n");
        wprintf(L"       %s 6\n", argv[0]);
        exit(1);
    }

    ifIndex = _wtoi(argv[1]);

    ifRow.InterfaceIndex = ifIndex;

    retVal = GetIfEntry2(&ifRow);

    if (retVal != NO_ERROR) {
        wprintf(L"GetIfEntry returned error: %lu\n", retVal);
        exit(1);
    }
    else
        wprintf(L"GetIfEntry2 function returned okay\n");
    
    PrintIfEntry2(&ifRow);

    exit(0);
}

// Print some parameters from the MIB_IF_ROW2 structure
void PrintIfEntry2(PMIB_IF_ROW2 pIfRow)
{

    int iRet = 0;
    WCHAR GuidString[40] = { 0 };

    unsigned int j;

    wprintf(L"\tInterfaceIndex:\t %lu\n", pIfRow->InterfaceIndex);

    iRet = StringFromGUID2(pIfRow->InterfaceGuid, (LPOLESTR) & GuidString, 39);
    // For c rather than C++ source code, the above line needs to be
    // iRet = StringFromGUID2(&pIfRow->InterfaceGuid, (LPOLESTR) &GuidString, 39); 
    if (iRet == 0)
        wprintf(L"StringFromGUID2 failed\n");
    else {
        wprintf(L"\tInterfaceGUID:   %ws\n", GuidString);
    }

    wprintf(L"\tAlias:\t\t %ws", pIfRow->Alias);
    wprintf(L"\n");
    wprintf(L"\tDescription:\t %ws", pIfRow->Description);
    wprintf(L"\n");
    wprintf(L"\tPhysical Address:\t    ");
    if (pIfRow->PhysicalAddressLength == 0)
        wprintf(L"\n");
    for (j = 0; j < (int) pIfRow->PhysicalAddressLength; j++) {
        if (j == (pIfRow->PhysicalAddressLength - 1))
            wprintf(L"%.2X\n", (int) pIfRow->PhysicalAddress[j]);
        else
            wprintf(L"%.2X-", (int) pIfRow->PhysicalAddress[j]);
    }
    wprintf(L"\tPermanent Physical Address: ");
    if (pIfRow->PhysicalAddressLength == 0)
        wprintf(L"\n");
    for (j = 0; j < (int) pIfRow->PhysicalAddressLength; j++) {
        if (j == (pIfRow->PhysicalAddressLength - 1))
            wprintf(L"%.2X\n", (int) pIfRow->PermanentPhysicalAddress[j]);
        else
            wprintf(L"%.2X-", (int) pIfRow->PermanentPhysicalAddress[j]);
    }
    wprintf(L"\tMtu:\t\t %lu\n", pIfRow->Mtu);

    wprintf(L"\tType:\t\t ");
    switch (pIfRow->Type) {
    case IF_TYPE_OTHER:
        wprintf(L"Other\n");
        break;
    case IF_TYPE_ETHERNET_CSMACD:
        wprintf(L"Ethernet\n");
        break;
    case IF_TYPE_ISO88025_TOKENRING:
        wprintf(L"Token Ring\n");
        break;
    case IF_TYPE_PPP:
        wprintf(L"PPP\n");
        break;
    case IF_TYPE_SOFTWARE_LOOPBACK:
        wprintf(L"Software Lookback\n");
        break;
    case IF_TYPE_ATM:
        wprintf(L"ATM\n");
        break;
    case IF_TYPE_IEEE80211:
        wprintf(L"IEEE 802.11 Wireless\n");
        break;
    case IF_TYPE_TUNNEL:
        wprintf(L"Tunnel type encapsulation\n");
        break;
    case IF_TYPE_IEEE1394:
        wprintf(L"IEEE 1394 Firewire\n");
        break;
    default:
        wprintf(L"Unknown type %ld\n", pIfRow->Type);
        break;
    }

    wprintf(L"\tTunnel Type:\t ");
    switch (pIfRow->TunnelType) {
    case TUNNEL_TYPE_NONE:
        wprintf(L"Not a tunnel\n");
        break;
    case TUNNEL_TYPE_OTHER:
        wprintf(L"None of the known tunnel types\n");
        break;
    case TUNNEL_TYPE_DIRECT:
        wprintf(L"Encapsulated directly within IPv4\n");
        break;
    case TUNNEL_TYPE_6TO4:
        wprintf
            (L"IPv6 packet encapsulated within IPv4 using 6to4 protocol\n");
        break;
    case TUNNEL_TYPE_ISATAP:
        wprintf
            (L"IPv6 packet encapsulated within IPv4 using ISATAP protocol\n");
        break;
    case TUNNEL_TYPE_TEREDO:
        wprintf(L"Teredo encapsulation\n");
        break;
    default:
        wprintf(L"Unknown tunnel type %ld\n", pIfRow->TunnelType);
        break;
    }

    wprintf(L"\tNDIS Media Type:\t ");
    switch (pIfRow->MediaType) {
    case NdisMedium802_3:
        wprintf(L"Ethernet (802.3)\n");
        break;
    case NdisMedium802_5:
        wprintf(L"Token Ring (802.5)\n");
        break;
    case NdisMediumFddi:
        wprintf(L"Fiber Distributed Data Interface (FDDI)\n");
        break;
    case NdisMediumWan:
        wprintf(L"Wide area network (WAN)\n");
        break;
    case NdisMediumLocalTalk:
        wprintf(L"LocalTalk\n");
        break;
    case NdisMediumDix:
        wprintf(L"Ethernet using DIX header format\n");
        break;
    case NdisMediumArcnetRaw:
        wprintf(L"ARCNET\n");
        break;
    case NdisMediumArcnet878_2:
        wprintf(L"ARCNET (878.2)\n");
        break;
    case NdisMediumAtm:
        wprintf(L"ATM\n");
        break;
    case NdisMediumWirelessWan:
        wprintf(L"Wireless WAN\n");
        break;
    case NdisMediumIrda:
        wprintf(L"Infrared (IrDA)\n");
        break;
    case NdisMediumBpc:
        wprintf(L"Broadcast PC\n");
        break;
    case NdisMediumCoWan:
        wprintf(L"Connection-oriented Wide Area Network (CoWAN)\n");
        break;
    case NdisMedium1394:
        wprintf(L"IEEE 1394 (fire wire)\n");
        break;
    case NdisMediumInfiniBand:
        wprintf(L"InfiniBand\n");
        break;
    case NdisMediumTunnel:
        wprintf(L"A Tunnel\n");
        break;
    case NdisMediumNative802_11:
        wprintf(L"Native IEEE 802.11\n");
        break;
    case NdisMediumLoopback:
        wprintf(L"NDIS loopback \n");
        break;
    default:
        wprintf(L"Unknown media type %ld\n", pIfRow->MediaType);
        break;
    }

    printf("\tAdministrative Status:\t ");
    switch (pIfRow->AdminStatus) {
    case NET_IF_ADMIN_STATUS_UP:
        wprintf(L"Interface up and enabled\n");
        break;
    case NET_IF_ADMIN_STATUS_DOWN:
        wprintf(L"Interface down\n");
        break;
    case NET_IF_ADMIN_STATUS_TESTING:
        wprintf(L"Interface in test mode\n");
        break;
    default:
        wprintf(L"Unknown status %ld\n", pIfRow->AdminStatus);
        break;
    }

    printf("\tMedia connection state:\t ");
    switch (pIfRow->MediaConnectState) {
    case MediaConnectStateUnknown:
        wprintf(L"Interface state is unknown\n");
        break;
    case MediaConnectStateConnected:
        wprintf(L"Connected\n");
        break;
    case MediaConnectStateDisconnected:
        wprintf(L"Disconnected\n");
        break;
    default:
        wprintf(L"Unknown state %ld\n", pIfRow->MediaConnectState);
        break;
    }

    wprintf(L"\tTransmit link speed:\t %I64u\n", pIfRow->TransmitLinkSpeed);
    wprintf(L"\tReceive link speed:\t %I64u\n", pIfRow->ReceiveLinkSpeed);

}

Requirements

Requirement Value
Minimum supported client Windows Vista [desktop apps | UWP apps]
Minimum supported server Windows Server 2008 [desktop apps | UWP apps]
Target Platform Windows
Header netioapi.h (include Iphlpapi.h)
Library Iphlpapi.lib
DLL Iphlpapi.dll

See also

GetIfEntry

GetIfTable

GetIfTable2

GetIfTable2Ex

IP Helper Function Reference

MIB_IFROW

MIB_IFTABLE

MIB_IF_ROW2

MIB_IF_TABLE2