实现linux服务器之间无密码互访

最近老是在群里看到许多同学问，linux之间无密码互访怎么弄啊，百度的看得我头晕之类的，所以我就写写怎么样在两台linux服务器之间实现无密码互访，也就是让它们互相信任的意思，废话不多说，直接上菜。

环境介绍

两台CentOS服务器，主机名和IP分别是： server1 192.168.1.69 server2 192.168.1.70

准备

1. #两台都要安装
2. yum install -y openssh-clients

分别打开两台服务器的hosts文件，在文件末尾添加以下内容，让主机名和IP对应。（还有就是别忘了分别修改两台服务器的/etc/sysconfig/network文件里的HOSTNAME，改成对应的服务器的主机名即可。）

1. vim /etc/hosts
2. server1 192.168.1.69
3. server2 192.168.1.70

开始

准备工作做好了，现在就可以开工了，首先在server1运行ssh-keygen，直接一路回车

1. [root@server1 ~]# ssh-keygen
2. Generating public/private rsa key pair.
3. Enter file in which to save the key (/root/.ssh/id_rsa):
4. Created directory '/root/.ssh'.
5. Enter passphrase (empty for no passphrase):
6. Enter same passphrase again:
7. Your identification has been saved in /root/.ssh/id_rsa.
8. Your public key has been saved in /root/.ssh/id_rsa.pub.
9. The key fingerprint is:
10. d8:0c:6c:f8:44:a3:61:c3:53:5c:09:93:2d:1d:d1:82 root@server1
11. The key's randomart image is:
12. +--[ RSA 2048]----+
13. | .+o*B+= |
14. | .oBEo= . |
15. | o.=. . |
16. | + = |
17. | o S |
18. | |
19. | |
20. | |
21. | |
22. +-----------------+

切换到server2，同上。

回到server1，运行ssh-copy-id -i .ssh/id_rsa.pub root@server2

1. [root@server1 ~]# ssh-copy-id -i .ssh/id_rsa.pub root@server2
2. The authenticity of host 'server2 (192.168.1.70)' can't be established.
3. RSA key fingerprint is 99:3b:ea:56:48:73:07:08:79:1f:69:b7:f2:a8:01:5c.
4. Are you sure you want to continue connecting (yes/no)? yes
5. Warning: Permanently added 'server2,192.168.1.70' (RSA) to the list of known hosts.
6. root@server2's password: #输入对方服务器root密码
7. Now try logging into the machine, with "ssh 'root@server2'", and check in:
8. .ssh/authorized_keys
9. to make sure we haven't added extra keys that you weren't expecting.

切换到server2，运行ssh-copy-id -i .ssh/id_rsa.pub root@server1

现在，你就可以不需要输入对方服务器的密码而直接登录了，试试看吧 O(∩_∩)O