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Java Code to Get MAC Address From Target IP Address

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MAC Address is a Unique identification of a Device. Computer, Mobile, Tablet, PC all have a Unique MAC Address. If you want to know about MAC Address here is some, MAC on Wiki. MAC Address is generally 48 bits long eg, 00:ff:a3:f0:76:ae
Here we are going to discuss about How to get that address by using supplied IP Address over the network.
Here is the Java Code
GetMACAddress.java

import java.net.Inet4Address;
import java.net.InetAddress;
import java.util.Arrays;

import jpcap.*;
import jpcap.packet.*;

public class GetMACAddress{
    public static byte[] arp(InetAddress ip) throws java.io.IOException{
        //find network interface
        NetworkInterface[] devices=JpcapCaptor.getDeviceList();
        NetworkInterface device=null;

loop:    for(NetworkInterface d:devices){
            for(NetworkInterfaceAddress addr:d.addresses){
                if(!(addr.address instanceof Inet4Address)) continue;
                byte[] bip=ip.getAddress();
                byte[] subnet=addr.subnet.getAddress();
                byte[] bif=addr.address.getAddress();
                for(int i=0;i<4;i++){
                    bip[i]=(byte)(bip[i]&subnet[i]);
                    bif[i]=(byte)(bif[i]&subnet[i]);
                }
                if(Arrays.equals(bip,bif)){
                    device=d;
                    break loop;
                }
            }
        }
      
        if(device==null)
            throw new IllegalArgumentException(ip+" is not a local address");
      
        //open Jpcap
        JpcapCaptor captor=JpcapCaptor.openDevice(device,2000,false,3000);
        captor.setFilter("arp",true);
        JpcapSender sender=captor.getJpcapSenderInstance();
      
        InetAddress srcip=null;
        for(NetworkInterfaceAddress addr:device.addresses)
            if(addr.address instanceof Inet4Address){
                srcip=addr.address;
                break;
            }

        byte[] broadcast=new byte[]{(byte)255,(byte)255,(byte)255,(byte)255,(byte)255,(byte)255};
        ARPPacket arp=new ARPPacket();
        arp.hardtype=ARPPacket.HARDTYPE_ETHER;
        arp.prototype=ARPPacket.PROTOTYPE_IP;
        arp.operation=ARPPacket.ARP_REQUEST;
        arp.hlen=6;
        arp.plen=4;
        arp.sender_hardaddr=device.mac_address;
        arp.sender_protoaddr=srcip.getAddress();
        arp.target_hardaddr=broadcast;
        arp.target_protoaddr=ip.getAddress();
      
        EthernetPacket ether=new EthernetPacket();
        ether.frametype=EthernetPacket.ETHERTYPE_ARP;
        ether.src_mac=device.mac_address;
        ether.dst_mac=broadcast;
        arp.datalink=ether;
      
        sender.sendPacket(arp);
      
        while(true){
            ARPPacket p=(ARPPacket)captor.getPacket();
            if(p==null){
                throw new IllegalArgumentException(ip+" is not a local address");
            }
            if(Arrays.equals(p.target_protoaddr,srcip.getAddress())){
                return p.sender_hardaddr;
            }
        }
    }
      
    public static void main(String[] args) throws Exception{
        if(args.length<1){
            System.out.println("Usage: java GetMACAddress <ip address>");
        }else{
            byte[] mac=GetMACAddress.arp(InetAddress.getByName(args[0]));
            for (byte b : mac)
                System.out.print(Integer.toHexString(b&0xff) + ":");
            System.out.println();
            System.exit(0);
        }
    }
}
To run this you need to get a library called WinPCap from winpcap.org for Windows or LibPCap for Linux. And more over you need to get a Java Library JPCap from Click Here .


If you have both these Library installed on your system then you can compile and run.
E:\>javac GetMACAddress.java


E:\>java GetMACAddress 192.168.174.94
0:21:97:8f:1b:a7:
E:\>


This is How you can get a MAC address from any machines from your Network/LAN.


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