前提，至少两台服务器。
如：
host1： 10.1.2.1
host2： 10.1.2.2
已centos7为例：
1、在host1重新生成ssh相关key文件，输入一下命令，一路回车。
[root@mmyr ~]# 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 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:
SHA256:fK7Ej96N4UzY216O70X/ipytWyfBRkjGnbH+yoUuvIs [email protected]
The key's randomart image is:
+---[RSA 2048]----+
| .o..o |
| o..o. |
| . o |
| . + |
| S . = .|
| . = . =.|
| + =. = *|
| . O Oo@ *.|
| .+ E.&OX..|
+----[SHA256]-----+
2、上传公钥到host2服务器。
>ssh-copy-id -i /root/.ssh/id_rsa.pub -p 22 [email protected]
3、验证登入
> ssh [email protected]
4、在host2上重复步骤1、2，完成免密登入。
转载于:https://www.jianshu.com/p/29b11118f2ed