TCP/22
SSH 应用层协议
作用：远程连接设备， 方便操作
服务器管理方式:
1、本地管理方式
安装系统、故障修复
[root@localhost ~]# netstat -antp | grep ssh tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1234/sshd tcp 0 52 192.168.22.130:22 192.168.22.1:53680 ESTABLISHED 4986/sshd: root@pts tcp6 0 0 :::22 :::* LISTEN 1234/sshd
在nide01上生成密钥对
[root@node01 ~]# ssh-keygen Generating public/private rsa key pair. Enter file in which to save the key (/root/.ssh/id_rsa): Created directory '/root/.ssh'. 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: 5c:0a:16:3d:f7:47:c8:74:a4:8a:fa:66:53:09:de:f1 root@node01.linux.com The key's randomart image is: +--[ RSA 2048]----+ | .. o.oo | | .o . oo. | | o o.... | | . o.+... . | | .So.+ . | | .. + E | | . . | | .+ | | o.. | +-----------------+
[root@node01 ~]# ls /root/.ssh/
id_rsa id_rsa.pub
将公钥拷给node02
[root@node01 ~]# ssh-copy-id 192.168.22.130 The authenticity of host '192.168.22.130 (192.168.22.130)' can't be established. ECDSA key fingerprint is 33:43:0a:ba:e1:1a:c3:d4:d7:3d:dc:74:af:b2:25:e0. Are you sure you want to continue connecting (yes/no)? yes /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys root@192.168.22.130's password: Number of key(s) added: 1 Now try logging into the machine, with: "ssh '192.168.22.130'" and check to make sure that only the key(s) you wanted were added.
在node02上在生成密钥对
[root@node02 ~]# ssh-keygen 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:+z5gNQiMn+HVdVvgHRDDtQLr493j/XdK/T5E99jX3Ak root@node02.linux.com The key's randomart image is: +---[RSA 2048]----+ | o . oo+*+.| | . + . . o+.+o| | o = . . .o..| | + . + E...| | S. + o+*| | o.. o o+B| | ... . .ooo| | .. ...*| | .o. .+X| +----[SHA256]-----+
将node02的公钥拷给node01
[root@node02 ~]# ssh-copy-id 192.168.22.129 /usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub" The authenticity of host '192.168.22.129 (192.168.22.129)' can't be established. ECDSA key fingerprint is SHA256:I2eTYpUvbeL3hyiiEqs1rl/t7pHJc+SCVNTwEUhmN0g. ECDSA key fingerprint is MD5:a3:3e:a0:47:f5:33:2f:a7:d7:68:5b:e3:28:09:01:6f. Are you sure you want to continue connecting (yes/no)? yes /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys root@192.168.22.129's password: Number of key(s) added: 1 Now try logging into the machine, with: "ssh '192.168.22.129'" and check to make sure that only the key(s) you wanted were added.
查看node01中的authorized_keys文件中含有node02的公钥信息
[root@node01 ~]# cat /root/.ssh/authorized_keys ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQChT+UMdHs0nFFzzWH+4aXdm6qx2vtkmpma+oYF6pabbTcDX1GbZYzqmSyLz7X5O9L8kpgJGXC6jK77jTYIjlHAIzjKSy59rg CdAOHOrxN68ntXmuJIdnNJVIbcsCBLP+IB21Vyv+OUL20E/vBAGOYDEvA38PI+iddvNLYM7FuJXL8VCspTEbCIMEs+HUa1V8qzNQS/fNxD9tWLxFAiHu73lz3BX2ZED0iSOq9l/sD42epY93NJv4YblAcIcHuSeIa1m0dPpFULMnX/UDKK+ChKua3TMitHScujg/A0X3upvIEMQ38TdlsyxNb2ETN+DlVLHQ6356vzSMweR2BwNhG/ root@node02.linux.com
同理在node02上也能查看到node01的公钥
[root@node02 ~]# cat /root/.ssh/authorized_keys ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDPrj8cI8RhKLBgYg8gZ+gj3dpm1/dq3eHNTOyYreiGDSnD+bzO/2biTc/mzSjFBNtbTcwx9/g+Qle60xTZo2l7F4oWNAafMR O2sY7cc8sIvr3avqVOkSo/mtFj5cFoIq6+f/+DBk3DveJfQ2wfwf+GWsBedgWh19LO/vvufteyP03P8ZdJmbPdaEf8UjusV/pDM26z7lKrLFESwMm/QtRzHqUKU7HVWCgl3Nt8SYivZ7qJODEof83UVceAs5dDOLmgVjubolb5RzN0zQvVT8C1o0zyGtU2/97OrVwZ7yN+/46PluKlzkWUgWXIlA8/9oV46rDh+fHxy4Lvl7yRr1+R root@node01.linux.com
在node01上免密登录node02成功
[root@node01 ~]# ssh root@192.168.22.130 Last login: Thu Jan 7 13:14:14 2021 from 192.168.22.1 [root@node02 ~]#
在node02上免密登录node01成功
[root@node02 ~]# ssh root@192.168.22.129 Last login: Thu Jan 7 13:14:22 2021 from 192.168.22.1 [root@node01 ~]#
完成以上操作就可以完成了两台ssh之间的免密登录。