为什么用gethostbyname得到只有127.0.1.1

Question

环境：vmware虚拟机+Ubuntu16.04

#include<stdio.h>
#include<unistd.h>
#include<netdb.h>
#include<sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define ERR_EXIT(m)\
do{\
    perror(m);\
    exit(EXIT_FAILURE);\  
}while(0);

int main()
{
        char hostname[256];
        gethostname(hostname,sizeof(hostname));
        printf("%s\n",hostname);


        struct hostent *hp;
        hp = gethostbyname(hostname);
        if(hp == NULL)
        {
                perror("gethostbyname");
        }

        int i=0;
        while(hp->h_addr_list[i]!=NULL){
                printf("hostname:%s\n",hp->h_name);
                printf("%d ip:%s\n",i,inet_ntoa(*(struct in_addr*)hp->h_addr_list[i]));
                i++;
        }

        return 0;
}

我得结果是

root@ubuntu:~/testWorkSpace/tcp_c/5_readline# ./gethostname 
ubuntu
hostname:ubuntu
0 ip:127.0.1.1

Answer 1

因为你是本机，一些网卡本机不走网络接口，所以是127.0.0.1，你要连另一个机器