移植的网上的程序，PC端使用调试助手做服务端，查看可以ping通但是无法建立联系，请问大佬们是什么原因

#include "lwip/netif.h"
#include "lwip/ip.h"
#include "lwip/tcp.h"
#include "lwip/init.h"
#include "netif/etharp.h"
#include "lwip/udp.h"
#include "lwip/pbuf.h"
#include <stdio.h>
#include <string.h>
#include "main.h"





static void client_err(void *arg, err_t err)       //³öÏÖ´íÎóʱµ÷ÓÃÕâ¸öº¯Êý£¬´òÓ¡´íÎóÐÅÏ¢£¬²¢³¢ÊÔÖØÐÂÁ¬½Ó
{
  printf("Á¬½Ó´íÎó!!\n");
    printf("³¢ÊÔÖØÁ¬!!\n");

  //Á¬½Óʧ°ÜµÄʱºòÊÍ·ÅTCP¿ØÖÆ¿éµÄÄÚ´æ
    printf("¹Ø±ÕÁ¬½Ó£¬ÊÍ·ÅTCP¿ØÖÆ¿éÄÚ´æ\n");
  //tcp_close(client_pcb);


  //ÖØÐÂÁ¬½Ó
    printf("ÖØгõʼ»¯¿Í»§¶Ë\n");
    TCP_Client_Init();

}


static err_t client_send(void *arg, struct tcp_pcb *tpcb)   //·¢Ëͺ¯Êý£¬µ÷ÓÃÁËtcp_writeº¯Êý
{
  uint8_t send_buf[]= "ÎÒÊÇ¿Í»§¶Ë\n";

  //·¢ËÍÊý¾Ýµ½·þÎñÆ÷
  tcp_write(tpcb, send_buf, sizeof(send_buf), 1); 

  return ERR_OK;
}

static err_t client_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)
{
  if (p != NULL) 
  {      
    /* ½ÓÊÕÊý¾Ý*/
    tcp_recved(tpcb, p->tot_len);

    /* ·µ»Ø½ÓÊÕµ½µÄÊý¾Ý*/  
    tcp_write(tpcb, p->payload, p->tot_len, 1);

    memset(p->payload, 0 , p->tot_len);
    pbuf_free(p);
  } 
  else if (err == ERR_OK) 
  {
    //·þÎñÆ÷¶Ï¿ªÁ¬½Ó
    printf("·þÎñÆ÷¶Ï¿ªÁ¬½Ó!\n");
    tcp_close(tpcb);

    //ÖØÐÂÁ¬½Ó
    TCP_Client_Init();
  }
  return ERR_OK;
}

static err_t client_connected(void *arg, struct tcp_pcb *pcb, err_t err)
{
  printf("connected ok!\n");

  //×¢²áÒ»¸öÖÜÆÚÐԻص÷º¯Êý
  tcp_poll(pcb,client_send,2);

  //×¢²áÒ»¸ö½ÓÊÕº¯Êý
  tcp_recv(pcb,client_recv);

  return ERR_OK;
}


void TCP_Client_Init(void)
{      
    struct tcp_pcb *client_pcb = NULL;   //ÕâÒ»¾äÒ»¶¨Òª·ÅÔÚÀïÃ棬·ñÔò»áûÓÃ
  ip4_addr_t server_ip;     //ÒòΪ¿Í»§¶ËÒªÖ÷¶¯Á¬½Ó·þÎñÆ÷£¬ËùÒÔÒªÖªµÀ·þÎñÆ÷µÄIPµØÖ·
  /* ´´½¨Ò»¸öTCP¿ØÖÆ¿é  */
  client_pcb = tcp_new();     

  IP4_ADDR(&server_ip, DEST_IP_ADDR0,DEST_IP_ADDR1,DEST_IP_ADDR2,DEST_IP_ADDR3);//ºÏ²¢IPµØÖ·

  printf("¿Í»§¶Ë¿ªÊ¼Á¬½Ó!\n");

  //¿ªÊ¼Á¬½Ó
  tcp_connect(client_pcb, &server_ip, TCP_CLIENT_PORT, client_connected);
    ip_set_option(client_pcb, SOF_KEEPALIVE);

    printf("ÒѾ­µ÷ÓÃÁËtcp_connectº¯Êý\n");

  //×¢²áÒì³£´¦Àí
  tcp_err(client_pcb, client_err);
    printf("ÒѾ­×¢²áÒì³£´¦Àíº¯Êý\n");
}