Retrieving network adapter info using the IP Helper API

Here’s a code snippet that enumerates the currently enabled network adapters and shows some info for each adapter :-

PIP_ADAPTER_INFO pAdapterInfo = NULL;
ULONG OutBufLen = 0;

//Get the required size of the buffer
if( GetAdaptersInfo(NULL, &OutBufLen) == ERROR_BUFFER_OVERFLOW )
{
  int divisor = sizeof IP_ADAPTER_INFO;

  /*** Uncomment for VC++ 2005 Beta 2
  if( sizeof time_t == 8 )
    divisor -= 8;
  ***/

  pAdapterInfo = new IP_ADAPTER_INFO[OutBufLen/divisor];

  //Get info for the adapters
  if( GetAdaptersInfo(pAdapterInfo, &OutBufLen) != ERROR_SUCCESS )
  {
    //Call failed
    delete[] pAdapterInfo;
    pAdapterInfo = NULL;
  }
  else
  {
    int index = 0;
    while(pAdapterInfo)
    {
      cout << pAdapterInfo->Description << endl;
      cout << pAdapterInfo->AdapterName << endl;

      cout << "MAC Address : ";
      for(int i=0; i < (int)pAdapterInfo->AddressLength; i++)
        cout << setfill('0') << setw(2) << uppercase <<  hex
          << (int)pAdapterInfo->Address[i] << ' ';
      cout << endl;

      cout << "Default Gateway : ";
      cout << pAdapterInfo->GatewayList.IpAddress.String << endl;

      cout << "IP Address list : ";
      PIP_ADDR_STRING pIpStr = &pAdapterInfo->IpAddressList;
      while(pIpStr)
      {
        cout << pIpStr->IpAddress.String << endl;
        pIpStr = pIpStr->Next;
      }


      pAdapterInfo = pAdapterInfo->Next;
      cout << endl << endl;

      //...

      delete[] pAdapterInfo;
    }
  }
}

I have only used some of the fields in the IP_ADAPTER_INFO structure, so make sure you look it up on MSDN.

BTW I used code similar to the above snippet in my MAC Address Changer for Windows XP/2003 application available as a free tool with source code from this Code Project article.