1、 生成公钥：ssh-keygen -t rsa 然后一直回车即可

_>: ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
e2:7b:a6:7d:2a:ca:32:dc:ad:f2:58:0c:c6:46:db:58 root@hadoop72
The key's randomart image is:
+--[ RSA 2048]----+
|                 |
|                 |
|  . E            |
| o =             |
|  B . . S        |
| o o . .         |
| . .o..          |
|  =+. ooo .      |
|  .==oo=oo       |
+-----------------+

2、 将公钥分配到机器中：ssh-copy-id test02 分配到本机与其他机器

ssh-copy-id test02

3、在test02机器上做一样的操作 ssh-copy-id test01 回来

4、SSH test02 就不需要输入密码

谢谢