ssh两台主机建立信任关系

A主机(10.104.11.107)   B主机（10.104.11.128）

A: ssh-keygen -t rsa

[root@H0f .ssh]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): /root/.ssh/id_rsa
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:
c3:41:52:b3:6c:0e:ca:37:87:c6:18:7c:80:6e:fb:1e root@H0f
The key's randomart image is:
+--[ RSA 2048]----+
|   .. ..+        |
|  .. . + o       |
| .  o o =        |
|  o. * * .       |
| . .+ * S        |
|  .  o o .       |
|   .E            |
|    ..           |
|   ..            |
+-----------------+

[root@H0f .ssh]# ll
total 12
-rw-------. 1 root root 1743 Mar 26 03:06 id_rsa    #密钥
-rw-r--r--. 1 root root  390 Mar 26 03:06 id_rsa.pub  #公钥
-rw-r--r--. 1 root root  395 Mar 26 03:08 known_hosts

[root@H0f .ssh]# scp -r id_rsa.pub 10.104.11.107:/root/.ssh/authorized_keys
root@10.104.11.107's password: #输入主机B的登录密码
id_rsa.pub

B：ssh-keygen -t rsa

[root@H0f .ssh]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): /root/.ssh/id_rsa
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:
c3:41:52:b3:6c:0e:ca:37:87:c6:18:7c:80:6e:fb:1e root@H0f
The key's randomart image is:
+--[ RSA 2048]----+
|   .. ..+        |
|  .. . + o       |
| .  o o =        |
|  o. * * .       |
| . .+ * S        |
|  .  o o .       |
|   .E            |
|    ..           |
|   ..            |
+-----------------+
[root@H0f .ssh]# ll
total 16
-rw-r--r-- 1 root root  390 Mar 26 04:00 authorized_keys
-rw------- 1 root root 1743 Mar 26 04:02 id_rsa
-rw-r--r-- 1 root root  390 Mar 26 04:02 id_rsa.pub
-rw-r--r-- 1 root root  395 Mar 26 03:10 known_hosts

[root@H0f .ssh]# scp -r id_rsa.pub 10.104.11.128:/root/.ssh/authorized_keys

root@10.104.11.128's password:
id_rsa.pub 

[root@H0f .ssh]# ssh 10.104.11.128   #建立连接
Enter passphrase for key '/root/.ssh/id_rsa':
Last login: Mon Mar 26 02:56:59 2018 from 10.104.10.85
[root@H0f ~]# ls
1_shell.sh  3_shuzu.sh    anaconda-ks.cfg    Documents   if.sh               Music     Templates  Videos
2_shell.sh  a_array.sh    danted_install.sh  Downloads   install.log         Pictures  testa
2.txt       aha_array.sh  Desktop            if_file.sh  install.log.syslog  Public    test.txt