Send TCP packet from PC to ethernet shield


Is anyone could help me on how to send tcp packet from my pc to ethernet shield?I've tried many times, but nothing was receive by the shield. this was what i did:

1)Connect my PC to ethernet shield via cross cable 2)generate TCP packet using Ostinato packet generator & send to the shield

from wireshark i noticed that it keeps on retransmit the same packet & nothing printed out on the serial monitor.

i also try to send UDP packet using library & examples from Bjorn, the results still the same.nothing received by the shield..

i'm using duemilanova 328 & ethernet shield. & i'm so sorry, caused i'm new to this programming things.


this is the codes that i use to send tcp packet to my shield from my PC. i modified server.cpp & .h to read the packet using socket. is anyone can help me? i need this so much…

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //MAC address of the shield
byte ip[] = { 169,254,131,123 }; //Ethernet shield IP address
Server server = 80; //server port to listen on

#define MAX_SIZE 32 // maximum packet size
byte packetBuffer[MAX_SIZE]; // buffer to hold incoming packet
int packetSize; // holds received packet size

int i;

/* SETUP: init Ethernet shield, Start TCP listening, open serial port */
void setup() {

/* LOOP: wait for incoming packets and print each packet to the serial port*/
void loop() 

  if(server.available()) {

    //if there's data available, read a packet
    packetSize =,MAX_SIZE);
      Serial.print("Received packet of size ");

      for(i=0; i<min(MAX_SIZE,abs(packetSize)); i++) {
  //wait a bit

thank you