IP_ADAPTER_ADDRESSES Structure

The IP_ADAPTER_ADDRESSES structure contains information about an adapter on the local computer. It is used with the GetAdaptersAddresses function to retrieve comprehensive details about network interfaces.

Header

#include <iphlpapi.h>

Library

Iphlpapi.lib

Syntax

typedef struct _IP_ADAPTER_ADDRESSES {
    ULONG                 Length;
    DWORD                 IfIndex;
    struct _IP_ADAPTER_ADDRESSES *Next;
    PWCHAR                AdapterName;
    PWCHAR                Description;
    UINT                  PhysicalAddressLength;
    BYTE                  PhysicalAddress[8];
    UINT                  Flags;
    DWORD                 Mtu;
    DWORD                 IfType;
    IF_OPER_STATUS        OperStatus;
    DWORD                 Ipv6IfIndex;
    DWORD                 ZoneIndices[16];
    PIP_ADAPTER_PREFIX    FirstPrefix;
    // ... (additional members omitted for brevity)
} IP_ADAPTER_ADDRESSES, *PIP_ADAPTER_ADDRESSES;

Members

Member	Type	Description
Length	ULONG	Size of the structure, in bytes.
IfIndex	DWORD	Interface index used to identify the adapter.
Next	struct _IP_ADAPTER_ADDRESSES*	Pointer to the next adapter in the list.
AdapterName	PWCHAR	Network adapter name (e.g., Ethernet0).
Description	PWCHAR	Human‑readable description of the adapter.
PhysicalAddressLength	UINT	Length, in bytes, of the physical address.
PhysicalAddress	BYTE[8]	MAC address of the adapter.
Flags	UINT	Adapter flags (e.g., IP_ADAPTER_IPV4_ENABLED).
Mtu	DWORD	Maximum Transmission Unit size.
IfType	DWORD	Network interface type (e.g., IF_TYPE_ETHERNET_CSMACD).
OperStatus	IF_OPER_STATUS	Operational status of the interface.
Ipv6IfIndex	DWORD	IPv6 interface index.
ZoneIndices	DWORD[16]	Per‑zone IPv6 interface indices.
FirstPrefix	PIP_ADAPTER_PREFIX	Pointer to the list of IPv4/IPv6 prefixes.

Example

The following C example retrieves all adapters and prints basic information.

#include <stdio.h>
#include <windows.h>
#include <iphlpapi.h>
#pragma comment(lib, "iphlpapi.lib")

int main() {
    ULONG outBufLen = 15000;
    PIP_ADAPTER_ADDRESSES pAddresses = NULL;
    DWORD dwRetVal = 0;

    pAddresses = (IP_ADAPTER_ADDRESSES *) malloc(outBufLen);
    if (pAddresses == NULL) {
        printf("Memory allocation failed.\n");
        return 1;
    }

    dwRetVal = GetAdaptersAddresses(AF_UNSPEC, GAA_FLAG_INCLUDE_PREFIX,
                                    NULL, pAddresses, &outBufLen);

    if (dwRetVal == NO_ERROR) {
        PIP_ADAPTER_ADDRESSES pCurr = pAddresses;
        while (pCurr) {
            printf("\nAdapter Name: %ws\n", pCurr->AdapterName);
            printf("Description : %ws\n", pCurr->Description);
            printf("IfIndex     : %u\n", pCurr->IfIndex);
            printf("OperStatus  : %u\n", pCurr->OperStatus);
            pCurr = pCurr->Next;
        }
    } else {
        printf("GetAdaptersAddresses failed with error: %u\n", dwRetVal);
    }

    if (pAddresses) free(pAddresses);
    return 0;
}

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