Program for Reverse Address Resolution Protocol (RARP) using UDP

Aim:

To write a java program for simulating RARP protocols using UDP

ALGORITHM:

Client

1.Start the program

2. using datagram sockets UDP function is established.

2.Get the MAC address to be converted into IP address.

3.Send this MAC address to server.

4.Server returns the IP address to client.

Server

1. Start the program.
2. Server maintains the table in which IP and corresponding MAC addresses are stored.
3. Read the MAC address which is send by the client.
4. Map the IP address with its MAC address and return the IP address to client.

Client:

import java.io.*; import java.net.*; import java.util.*; class Clientrarp12

{

public static void main(String args[])

{

try

{

DatagramSocket client=new DatagramSocket();

InetAddress addr=InetAddress.getByName("127.0.0.1"); byte[] sendbyte=new byte[1024];

byte[] receivebyte=new byte[1024];

BufferedReader in=new BufferedReader(new InputStreamReader(System.in)); System.out.println("Enter the Physical address (MAC):")

String str=in.readLine(); sendbyte=str.getBytes();

DatagramPacket sender=newDatagramPacket(sendbyte,sendbyte.length,addr,1309);

client.send(sender);

DatagramPacket receiver=new DatagramPacket(receivebyte,receivebyte.length); client.receive(receiver);

String s=new String(receiver.getData()); System.out.println("The Logical Address is(IP): "+s.trim()); client.close();

}

catch(Exception e)

{

System.out.println(e);

}

}

}

Server:

import java.io.*; import java.net.*; import java.util.*; class Serverrarp12

{

public static void main(String args[])

{

try

{

DatagramSocket server=new DatagramSocket(1309); while(true)

{

byte[] sendbyte=new byte[1024];

byte[] receivebyte=new byte[1024];

DatagramPacket receiver=new DatagramPacket(receivebyte,receivebyte.length);

server.receive(receiver);

String str=new String(receiver.getData()); String s=str.trim();

InetAddress addr=receiver.getAddress();

int port=receiver.getPort();

String ip[]={"165.165.80.80","165.165.79.1"}; String mac[]={"6A:08:AA:C2","8A:BC:E3:FA"}; for(int i=0;i<ip.length;i++)

{

if(s.equals(mac[i]))

{

sendbyte=ip[i].getBytes();

DatagramPacket sender=newDatagramPacket(sendbyte,sendbyte.length,addr,port);

server.send(sender);

break;

}

}

break;

}

}

catch(Exception e)

{

System.out.println(e);

}

}

}

Output:

I:\ex>java Serverrarp12

I:\ex>java Clientrarp12

Enter the Physical address (MAC): 6A:08:AA:C2

The Logical Address is(IP): 165.165.80.80