What is the problem with this server program?

#include<stdio.h>
#include<stdlib.h>
#include<netinet/in.h>
#include<sys/types.h>
#include<sys/socket.h>
 
int main()
{
    int fd_server, fd_client, len;
    struct sockaddr_in add_server;
    fd_server = socket(AF_INET,SOCK_STREAM,0);
    if (fd_server == -1)
    {
        perror("fd_sock");
        exit(1);
    }
    add_server.sin_family = AF_INET;
    add_server.sin_port = htons(4001);
    add_server.sin_addr.s_addr = inet_addr("122.23.1.1");
    len = sizeof(add_server);
    if( bind(fd_server,(struct sockaddr*)&add_server,len) != 0)
        perror("bind");
    if(listen(fd_server,5) != 0)
        perror("listen");
    fd_client = accept(fd_server,(struct sockaddr*)&add_server,&len);
    if(fd_client == -1)
        perror("accept");
    return 0;
}