Get Mac Adress using IP Adress

//http://www.binarytides.com/get-mac-address-from-ip-in-winsock/
/*
Author: Silver Moon ( m00n.silv3r@gmail.com )
Find mac address of a given IP address using iphlpapi
*/

#include "winsock2.h"
#include "iphlpapi.h"   //For SendARP
#include "stdio.h"
#include "conio.h"

#pragma comment(lib , "iphlpapi.lib") //For iphlpapi
#pragma comment(lib , "ws2_32.lib") //For winsock

void GetMacAddress(unsigned char * , struct in_addr );

int main()
{
    unsigned char mac[6];
    struct in_addr srcip;
    char ip_address[32];

    WSADATA firstsock;

    if (WSAStartup(MAKEWORD(2,2),&firstsock) != 0)
    {
        printf("\nFailed to initialise winsock.");
        printf("\nError Code : %d" , WSAGetLastError() );
        return 1;
    }

    //Ask user to select the device he wants to use
    printf("Enter the ip address : ");
    scanf_s("%s",ip_address);
    srcip.s_addr = inet_addr(ip_address);

    //Get mac addresses of the ip
    GetMacAddress(mac , srcip);
    printf("Selected device has mac address : %.2X-%.2X-%.2X-%.2X-%.2X-%.2X",mac[0],mac[1],mac[2],mac[3],mac[4],mac[5]);
    printf("\n");

    _getch();
    return 0;
}

/*
    Get the mac address of a given ip
*/
void GetMacAddress(unsigned char *mac , struct in_addr destip)
{
    DWORD ret;
    IPAddr srcip;
    ULONG MacAddr[2];
    ULONG PhyAddrLen = 6;  /* default to length of six bytes */
    int i;

    srcip = 0;

    //Send an arp packet
    ret = SendARP((IPAddr) destip.S_un.S_addr , srcip , MacAddr , &PhyAddrLen);

    //Prepare the mac address
    if(PhyAddrLen)
    {
        BYTE *bMacAddr = (BYTE *) & MacAddr;
        for (i = 0; i < (int) PhyAddrLen; i++)
        {
            mac[i] = (char)bMacAddr[i];
        }
    }
}