#include <Ethernet.h>
    #include <SPI.h>

    // the media access control (ethernet hardware) address for the shield:
    byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
    //the IP address for the shield:
    byte ip[] = { 10, 0, 0, 177 };
    // the router's gateway address:
    byte gateway[] = { 10, 0, 0, 1 };
    // the subnet:
    byte subnet[] = { 255, 255, 0, 0 };


    // telnet defaults to port 23
    EthernetServer server = EthernetServer(23);

    void setup()
    {
      // initialize the ethernet device
      Ethernet.begin(mac, ip, gateway, subnet);

      // start listening for clients
      server.begin();
    }

    void loop()
    {
      // if an incoming client connects, there will be bytes available to read:
      EthernetClient client = server.available();
      if (client == true) {
        // read bytes from the incoming client and write them back
        // to any clients connected to the server:
        server.write(client.read());
      }
    }