Centos SSH Password-free interoperability

Note: SSH password-free interoperability, should be for more than one server communication, I only use a server to do processing. 1, modify the host name.

Vi/etc/sysconfig/network
Networking=yes
hostname=centos1

vi/etc/hosts
#末尾添加 IP host name
192.168.9.129 CENTOS1

Hostname centos1 
#修改主机名临时生效

2, no password login implementation 2.1. Create Public key with Ssh-keygen (each server needs to be executed)

[Root@centos1 ~]# ssh-keygen-t RSA  
generating public/private RSA key pair.
Enter file in which to save the key (/ROOT/.SSH/ID_RSA): 
Enter passphrase (empty for no passphrase): 
enter same PA Ssphrase again: 
Your identification has been saved.
Your public key has been saved in/root/.ssh/id_rsa.pub.
The key fingerprint is:
a0:85:f4:58:d4:c7:2f:d9:ae:b1:04:91:b1:a0:9e:93 root@centos1 the
key ' s Randomart Image is:
+--[RSA 2048]----+
|    . +.. +       |
|   . *. +.O      |
|    + +. O +     |
|   . =. o O    |    | E   S. o     |
|     .    O.    |
|         . +     |
|          o                 |
| | +-----------------+

Password-free interoperability, direct return to complete.

Ssh-keygen: Generate secret key
which
-t specifies an algorithm
-f Specifies the build secret key path
-N Specify password 2.2, view the generated key

[Root@centos1 ~]# CD. ssh/
[root@centos1. ssh]# ls
id_rsa  id_rsa.pub  known_hosts

2.3 Copy the public key to the. SSH directory under the managed machine (make sure this directory exists first)

I am a stand-alone machine here, so I do not need to do this procedure.

Then execute

[ROOT@CENTOS1. ssh]# cat id_rsa.pub >> ~/.ssh/authorized_keys  
[root@centos1. ssh]# ls
authorized_keys  id_rsa  id_rsa.pub  known_hosts

4. Set file and directory permissions:

Set Authorized_keys Permissions

chmod Authorized_keys   

setting. SSH Directory Permissions

chmod 700-r. SSH  

Verify success

[ROOT@CENTOS1. ssh]# ssh centos1 last
login:thu Dec 10:15:52 2015 from 192.168.9.1