Arduino Ethernet 在IDE 0021 和W5100 ethernet shield与PC机串口测试时连接失败...

坐看牛郎织女星

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

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
byte ip[] = { 192, 168, 1, 102 };
byte server[] = { 222, 139, 215, 195 };

Client client(server, 2080);

void setup()
{
  Ethernet.begin(mac, ip);
  Serial.begin(9600);
  Serial.println("starting simple arduino client test");
  Serial.println();

  delay(1000);

  Serial.println("connecting...");

  if (client.connect()) {
    Serial.println("connected");
    client.println("GET /~shb/arduino.txt HTTP/1.0");
    client.println();
  } else {
    Serial.println("connection failed");
  }
}

void loop()
{
  if (client.available()) {
    char c = client.read();
    Serial.print(c);
  }

  if (!client.connected()) {
    Serial.println();
    Serial.println("disconnecting.");
    client.stop();
    for(;;);
  }
}

观察结果为：
starting simple arduino client test

connecting...
connection failed


如何解决？
disconnecting.