linux下实现免密传输文件或登录到其他服务器

使用scp传输文件到其他服务器的时候，提示需要输密码，如下：

[root@18c setup]# scp linux.X64_180000_db_home.zip 192.168.133.120:/u01

root@192.168.133.120's password:

每次都要输，很麻烦，我们可以建立两台服务器之间的互信关系，实现免密传输或登录

步骤如下：

(1)A主机生成配对秘钥

[root@18c setup]# 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:

fb:00:4f:76:c5:73:da:ef:3a:e6:a4:b2:66:f9:94:26 root@18c

The key's randomart image is:

+--[ RSA 2048]----+

| |

| . |

| + . |

| . = |

| . S . . . |

| = o . . |

| + E.+ . .|

| o=+ oo. |

| oo+oooo.|

+-----------------+

[root@18c setup]#

（2）将/root/.ssh目录下生成的id_rsa.pub文件传输到B机的/root/.ssh下，如果B机不存在.ssh目录，需要手工创建，并且命名为authorized_keys

[root@18c .ssh]# scp id_rsa.pub 192.168.133.120:/root/.ssh/authorized_keys

root@192.168.133.120's password:

id_rsa.pub 100% 390 0.4KB/s 00:00

[root@18c .ssh]#

（3）验证从A机传输文件到B机，可以看到能免密传输

[root@18c setup]# scp LINUX.X64_180000_db_home.zip 192.168.133.120:/u01

LINUX.X64_180000_db_home.zip 22% 997MB 115.6MB/s 00:29 ETA^CKilled by signal 2.

免密登录

[root@18c setup]# ssh 192.168.133.120

Last login: Sat Sep 8 00:59:14 2018 from 192.168.133.111

[root@dbserver ~]#