背景：两台电脑，ip分别为：5， 10（简称）

目的：ip地址5服务器通过ssh远程访问10.无需输入密码

1、首先在5上生成密钥对。

#cd /root/.ssh
#ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): （直接回车）
Enter passphrase (empty for no passphrase): （直接回车）
Enter same passphrase again: （直接回车）
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:
06:96:6b:56:0c:33:a4:24:16:8c:06:35:9b:98:8b:e7 root@localhost.localdomain

2、在root/.ssh目录下生成密钥对 id_rsa和id_rsa.pub

其中id_rsa是私钥，id_rsa.pub是公钥。

3、将公钥直接copy到10的/root/.ssh目录下

#scp id_rsa.pub root@192.168.1.10:/root/.ssh

4、将10机器上的id_rsa.pub改名为authorized_keys

#cd /root/.ssh
#mv id_rsa.pub authorized_keys

5、密钥设置成功。5ssh访问10无需密码成功

#ssh 192.168.1.10