linux系統配置免密碼的方式：

1：ssh-keygen -t rsa

生成金鑰

[[email protected] ~]# 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:
5d:3c:0c:d1:c7:4d:b8:8c:7e:35:66:89:ae:75:fa:e8

2：ssh-copy-id  -i ~/.ssh/id_rsa.pub  [email protected]

把本機的公鑰追到116.255.34.112的 .ssh/authorized_keys 裡

[[email protected] ~]# ssh-copy-id  -i ~/.ssh/id_rsa.pub  [email protected]
 

3：測試

[[email protected] ]$ ssh 116.255.34.112
Last login: Thu Aug  7 16:37:55 2014 from 116.255.34.110
[

4：如果ssh的埠不是22，可用下面命令
[[email protected] ~]# ssh-copy-id  -i ~/.ssh/id_rsa.pub '-p 2200 [email protected]'

5.如線上伺服器會對ssh服務改成非22埠，這時候，在伺服器之間建立雙機互信的情況下，若使用ssh-copy-id命令，不經過特定的語法，會報錯。

比如:

[[email protected] ~]# ssh-copy-id -i  /root/.ssh/id_rsa.pub  '-p 20460 [email protected]*.*.*.*'
Now try logging into the machine, with "ssh '-p 10022 [email protected]*.*.*.*'", and check in:

  .ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.