Transfering data between PC (processing) and Arduino(Ethernet Shield, UDP)

I’m having some problems getting the Ethernet Shield (HR911105A) communicating with Processing using UDP. I’ve tried UdpNtpclient code on my Arduino mega.

The code I’m using is from the UDPSendReceiveString tutorial here:

I changed nothing in that code.

What happens is that the Arduino never receives the strings sent from Processing. Also, if I try sending strings from the Arduino, I never receive them from Processing.

Arduino code:

/*
 UDPSendReceiveString:
 This sketch receives UDP message strings, prints them to the serial port
 and sends an "acknowledge" string back to the sender

 A Processing sketch is included at the end of file that can be used to send
 and received messages for testing with a computer.

 created 21 Aug 2010
 by Michael Margolis

 This code is in the public domain.
 */


#include <SPI.h>         // needed for Arduino versions later than 0018
#include <Ethernet.h>
#include <EthernetUdp.h>         // UDP library from: bjoern@cs.stanford.edu 12/30/2008


// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
IPAddress ip(192, 168, 1, 177);

unsigned int localPort = 8888;      // local port to listen on

// buffers for receiving and sending data
char packetBuffer[UDP_TX_PACKET_MAX_SIZE];  //buffer to hold incoming packet,
char  ReplyBuffer[] = "acknowledged";       // a string to send back

// An EthernetUDP instance to let us send and receive packets over UDP
EthernetUDP Udp;

void setup() {
  // start the Ethernet and UDP:
  Ethernet.begin(mac, ip);
  Udp.begin(localPort);

  Serial.begin(9600);
}

void loop() {
  // if there's data available, read a packet
  int packetSize = Udp.parsePacket();
  if (packetSize) {
    Serial.print("Received packet of size ");
    Serial.println(packetSize);
    Serial.print("From ");
    IPAddress remote = Udp.remoteIP();
    for (int i = 0; i < 4; i++) {
      Serial.print(remote[i], DEC);
      if (i < 3) {
        Serial.print(".");
      }
    }
    Serial.print(", port ");
    Serial.println(Udp.remotePort());

    // read the packet into packetBufffer
    Udp.read(packetBuffer, UDP_TX_PACKET_MAX_SIZE);
    Serial.println("Contents:");
    Serial.println(packetBuffer);

    // send a reply to the IP address and port that sent us the packet we received
    Udp.beginPacket(Udp.remoteIP(), Udp.remotePort());
    Udp.write(ReplyBuffer);
    Udp.endPacket();
  }
  delay(10);
}

Processing code:

/*
  Processing sketch to run with this example
=====================================================

// Processing UDP example to send and receive string data from Arduino
// press any key to send the "Hello Arduino" message
*/

import hypermedia.net.*;

UDP udp;  // define the UDP object


void setup() {
   size(300,300);
   udp = new UDP( this, 6000 );  // create a new datagram connection on port 6000
   udp.log( true );         // <-- printout the connection activity
   udp.listen( true );           // and wait for incoming message 
}

void draw()
{
   background(0);
}

void keyPressed() {
String ip       = "192.168.1.177"; // the remote IP address
int port        = 8888;        // the destination port

println("sending Hello World");
udp.send("Hello World", ip, port );   // the message to send
}

void receive( byte[] data ) {          // <-- default handler
//void receive( byte[] data, String ip, int port ) {   // <-- extended handler

for(int i=0; i < data.length; i++)
print(char(data[i])); 
println();   
}

Pocessing console output:

sending Hello World
– UDP session started at Thu Feb 23 00:29:35 BDT 2017 –
– bound socket to host:null, port: 6000 –
[17-02-23 00:30:20.152 +0600] send packet → address:/192.168.1.177, port:8888, length: 11
sending Hello World
[17-02-23 00:31:15.841 +0600] send packet → address:/192.168.1.177, port:8888, length: 11
sending Hello World
[17-02-23 00:31:16.24 +0600] send packet → address:/192.168.1.177, port:8888, length: 11

I’ve checked that my firewall is not blocking the port.
And my pc is running on Win 7.

Does your router know that the Arduino is at 192.168.1.177?

Do you think that my router is blocking the connection? I found no other advice like that on internet and i have been searching for 2 days. So, i didn't check it.
Can you tell how can i check it?
Note: I tried other codes on example like web server, UdpNtpclient they worked fine.