GetIpNetTable2 function (netioapi.h)

The GetIpNetTable2 function retrieves the IP neighbor table on the local computer.

Syntax

IPHLPAPI_DLL_LINKAGE _NETIOAPI_SUCCESS_ NETIOAPI_API GetIpNetTable2(
  [in]  ADDRESS_FAMILY    Family,
  [out] PMIB_IPNET_TABLE2 *Table
);

Parameters

[in] Family

The address family to retrieve.

Possible values for the address family are listed in the Winsock2.h header file. Note that the values for the AF_ address family and PF_ protocol family constants are identical (for example, AF_INET and PF_INET), so either constant can be used.

On the Windows SDK released for Windows Vista and later, the organization of header files has changed and possible values for this member are defined in the Ws2def.h header file. Note that the Ws2def.h header file is automatically included in Winsock2.h, and should never be used directly.

The values currently supported are AF_INET, AF_INET6, and AF_UNSPEC.

[out] Table

A pointer to a MIB_IPNET_TABLE2 structure that contains a table of neighbor IP address entries on the local computer.

Return value

If the function succeeds, the return value is NO_ERROR or ERROR_NOT_FOUND.

If the function fails or returns no data, the return value is one of the following error codes.

Remarks

The GetIpNetTable2 function is defined on Windows Vista and later.

The
GetIpNetTable2 function enumerates the neighbor IP addresses on a local system and returns this information in a MIB_IPNET_TABLE2 structure.

The neighbor IP address entries are returned in a MIB_IPNET_TABLE2 structure in the buffer pointed to by the Table parameter. The MIB_IPNET_TABLE2 structure contains a neighbor IP address entry count and an array of MIB_IPNET_ROW2 structures for each neighbor IP address entry. When these returned structures are no longer required, free the memory by calling the FreeMibTable.

The Family parameter must be initialized to either AF_INET, AF_INET6, or AF_UNSPEC.

Note that the returned MIB_IPNET_TABLE2 structure pointed to by the Table parameter may contain padding for alignment between the NumEntries member and the first MIB_IPNET_ROW2 array entry in the Table member of the MIB_IPNET_TABLE2 structure. Padding for alignment may also be present between the MIB_IPNET_ROW2 array entries. Any access to a MIB_IPNET_ROW2 array entry should assume padding may exist.

Examples

The following example retrieves the IP neighbor table, then prints the values for IP neighbor row entries in the table.

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif

#include <windows.h>
#include <winsock2.h>
#include <ws2ipdef.h>
#include <iphlpapi.h>
#include <stdio.h>
#include <stdlib.h>

#pragma comment(lib, "iphlpapi.lib")
#pragma comment(lib, "ws2_32.lib")

int main()
{

    // Declare and initialize variables

    int i;
    unsigned int j;
    unsigned long status = 0;

    PMIB_IPNET_TABLE2 pipTable = NULL;
//    MIB_IPNET_ROW2 ipRow;

    status = GetIpNetTable2(AF_INET, &pipTable);
    if (status != NO_ERROR) {
        printf("GetIpNetTable for IPv4 table returned error: %ld\n", status);
        exit(1);
    }
    // Print some variables from the table
    printf("Number of IPv4 table entries: %d\n\n", pipTable->NumEntries);

    for (i = 0; (unsigned) i < pipTable->NumEntries; i++) {
//        printf("Table entry: %d\n", i);
        printf("IPv4 Address[%d]:\t %s\n", (int) i,
               inet_ntoa(pipTable->Table[i].Address.Ipv4.sin_addr));
        printf("Interface index[%d]:\t\t %lu\n", (int) i,
               pipTable->Table[i].InterfaceIndex);

        printf("Interface LUID NetLuidIndex[%d]:\t %lu\n",
               (int) i, pipTable->Table[i].InterfaceLuid.Info.NetLuidIndex);
        printf("Interface LUID IfType[%d]: ", (int) i);
        switch (pipTable->Table[i].InterfaceLuid.Info.IfType) {
        case IF_TYPE_OTHER:
            printf("Other\n");
            break;
        case IF_TYPE_ETHERNET_CSMACD:
            printf("Ethernet\n");
            break;
        case IF_TYPE_ISO88025_TOKENRING:
            printf("Token ring\n");
            break;
        case IF_TYPE_PPP:
            printf("PPP\n");
            break;
        case IF_TYPE_SOFTWARE_LOOPBACK:
            printf("Software loopback\n");
            break;
        case IF_TYPE_ATM:
            printf("ATM\n");
            break;
        case IF_TYPE_IEEE80211:
            printf("802.11 wireless\n");
            break;
        case IF_TYPE_TUNNEL:
            printf("Tunnel encapsulation\n");
            break;
        case IF_TYPE_IEEE1394:
            printf("IEEE 1394 (Firewire)\n");
            break;
        default:
            printf("Unknown: %d\n",
                   pipTable->Table[i].InterfaceLuid.Info.IfType);
            break;
        }

        printf("Physical Address[%d]:\t ", (int) i);
        if (pipTable->Table[i].PhysicalAddressLength == 0)
            printf("\n");
//        for (j = 0; (unsigned) j < pipTable->Table[i].PhysicalAddressLength; j++)
//         printf ("%c" 
        for (j = 0; j < pipTable->Table[i].PhysicalAddressLength; j++) {
            if (j == (pipTable->Table[i].PhysicalAddressLength - 1))
                printf("%.2X\n", (int) pipTable->Table[i].PhysicalAddress[j]);
            else
                printf("%.2X-", (int) pipTable->Table[i].PhysicalAddress[j]);
        }

        printf("Physical Address Length[%d]:\t %lu\n", (int) i,
               pipTable->Table[i].PhysicalAddressLength);

        printf("Neighbor State[%d]:\t ", (int) i);
        switch (pipTable->Table[i].State) {
        case NlnsUnreachable:
            printf("NlnsUnreachable\n");
            break;
        case NlnsIncomplete:
            printf("NlnsIncomplete\n");
            break;
        case NlnsProbe:
            printf("NlnsProbe\n");
            break;
        case NlnsDelay:
            printf("NlnsDelay\n");
            break;
        case NlnsStale:
            printf("NlnsStale\n");
            break;
        case NlnsReachable:
            printf("NlnsReachable\n");
            break;
        case NlnsPermanent:
            printf("NlnsPermanent\n");
            break;
        default:
            printf("Unknown: %d\n", pipTable->Table[i].State);
            break;
        }

        printf("Flags[%d]:\t\t %u\n", (int) i,
               (unsigned char) pipTable->Table[i].Flags);

        printf("ReachabilityTime[%d]:\t %lu\n\n", (int) i,
               pipTable->Table[i].ReachabilityTime);

    }
    FreeMibTable(pipTable);
    pipTable = NULL;

    exit(0);
}

Requirements

See also

CreateIpNetEntry2

FlushIpNetTable2

FreeMibTable

GetIpNetEntry2

MIB_IPNET_ROW2

MIB_IPNET_TABLE2

ResolveIpNetEntry2

SetIpNetEntry2