DFRobot: Shield Ethernet V3.0 W5100S

        #include <SPI.h>
        #include <Ethernet.h>
        
        //Define digital output IO port
        uint8_t D2 =2;
        uint8_t D3 =3;
        int value = LOW;
        int value1 = LOW;
        
        // Enter a MAC address and IP address for your controller below.
        // The IP address will be dependent on your local network:
        byte mac[] = {0xDE, 0xCD, 0xAE, 0x0F, 0xFE, 0xED };
        
        // Initialize the Ethernet server library
        // with the IP address and port you want to use
        // (port 80 is default for HTTP):
        EthernetServer server(80);
        
        void setup() {
          // Open serial communications and wait for port to open:
          Serial.begin(9600);
          while (!Serial); // wait for serial port to connect. Needed for Leonardo only
          //Set digital IO port to output mode
          pinMode(D2,OUTPUT);
          pinMode(D3,OUTPUT);
          // start the Ethernet connection:
          if(Ethernet.begin(mac) == 0) {
            Serial.println("Failed to configure Ethernet using DHCP");
            // no point in carrying on, so do nothing forevermore:
            for(;;);
          }
          // print your local IP address:
          Serial.print("My IP address: ");
          for(byte thisByte = 0; thisByte < 4; thisByte++){
            // print the value of each byte of the IP address:
            Serial.print(Ethernet.localIP()[thisByte], DEC);
            Serial.print(".");
          }
          Serial.println();
        
          // start the Ethernet connection and the server:
        
          server.begin();
          Serial.print("server is at ");
          Serial.println(Ethernet.localIP());
        }
        
        
        void loop() {
          // listen for incoming clients
          EthernetClient client = server.available();
          String request;
          if(client){
            Serial.println("new client");
            // an http request ends with a blank line
            boolean currentLineIsBlank = true;
            while(client.connected()){
              if(client.available()){
                char c = client.read();
                Serial.write(c);
                request +=c; 
                // if you've gotten to the end of the line (received a newline
                // character) and the line is blank, the http request has ended,
                // so you can send a reply
                if (c == '\n' && currentLineIsBlank){
                  // send a standard http response header
                  client.println("HTTP/1.1 200 OK");
                  client.println("Content-Type: text/html");
                  client.println("Connnection: close");
                  client.println();
                  client.println("<!DOCTYPE HTML>");
                  client.println("<html>");
                  // add a meta refresh tag, so the browser pulls again every 5 seconds:
                  client.println("<meta http-equiv=\"refresh\" content=\"5\">");
                  client.println("<link rel=\"stylesheet\" type=\"text/css\" href=\"http://www.dfrobot.com/ihome/stylesheet/stylesheet.css\" />");
                  client.println("<center> <a href=\"http://www.dfrobot.com\"><img src=\"http://alturl.com/qf6vz\"></a> </center> ");
                  client.println("<br />");
                  client.println("<div>");
                  client.flush();
        /********************************Page display section***********************************/
                  //Determines whether there is information in the HTTP request that controls the output pins and, if so, sets the output state of the outlet based on the information
                  if(request.indexOf("GET /D2=ON") != -1){
                    digitalWrite(D2, HIGH);
                    value = HIGH;
                  } 
                  if(request.indexOf("GET /D2=OFF") != -1){
                    digitalWrite(D2, LOW);
                    value = LOW;
                  }
                  //Reply the status of the set digital IO port according to the request message
                  client.print("Digital_2 output: "); 
                  if(value == HIGH){
                    client.print("ON");  
                  } else{
                      client.print("OFF");
                  }
                  client.println("<br><br>");
                  //In the web page set control D2 port hyperlink, used for web control development board digital output IO port state
                  client.println("Turn <a href=\"/D2=ON\">ON</a><br>");
                  client.println("Turn <a href=\"/D2=OFF\">OFF</a><br>");
                  if(request.indexOf("GET /D3=ON") != -1) {
                    digitalWrite(D3, HIGH);
                    value1 = HIGH;
                  } 
                  if(request.indexOf("GET /D3=OFF") != -1){
                    digitalWrite(D3, LOW);
                    value1 = LOW;
                  }
                  client.println("<br />");
                  client.print("Digital_3 output: "); 
                  if(value1 == HIGH){
                    client.print("ON");  
                  } else{
                    client.print("OFF");
                  }
                  client.println("<br><br>");
                  client.println("Turn <a href=\"/D3=ON\">ON</a><br>");
                  client.println("Turn <a href=\"/D3=OFF\">OFF</a><br>");
        /****************************************************************************/
                  client.println("</html>");   
                  break;
                }
                if (c == '\n'){
                  // you're starting a new line
                  currentLineIsBlank = true;
                } else if (c != '\r'){
                  // you've gotten a character on the current line
                  currentLineIsBlank = false;
                }
              }
            }
            // give the web browser time to receive the data
            delay(1);
             //close the connection:
            client.stop();
            Serial.println("client disonnected");
          }
        }