服务器
什么是ssh
管理员可以通过远程登陆的方式，对通过网相连的分散于各处的多台主机进行管理操作。
管理员可以对远程主机进行如下操作：
远程登陆 远程命令执行 远程文件传输遗憾的事情是：这些操作不安全！
使用纯文本口令，并用明文发送
信息可能会被截取，口令可能会被检索 未经授权的人员使用截取的口令登陆系统而对系统造成危害在日常操作练习时，用ssh登录其他主机时，可能会每次都需要输入登录密码，哪怕用scp复制东西也需要。
为了更方便快捷的切换主机，ssh免密通信不失为更好的选择；
用ssh-keygen生成密钥，默认保存在本地的/root/.ssh/id_rsa
然后在用ssh-copy-id分发至目标主机之上；登录用户@主机名或IP地址
注意：
1.最好是用主机名，在/etc/hosts文件中写入主机名和对应的IP地址；
2.免密通信需要双方相互认证，所以也需要在目标主机对本机做一次相同的操作；
[root@www ~]# ssh-keygen -t rsa -P \'\' Generating public/private rsa key pair. Enter file in which to save the key (/root/.ssh/id_rsa): /root/.ssh/id_rsa already exists. Overwrite (y/n)?
[root@www ~]#ssh-copy-id -i .ssh/id_rsa.pub root@172.16.75.1 /usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: .ssh/id_rsa.pub The authenticity of host \'172.16.75.1 (172.16.75.1)\' can\'t be established. ECDSA key fingerprint is SHA256:YXhbTS9MfK2IQC4gtOW4RL8voHvFqC1cAAMJXuF3Wec. ECDSA key fingerprint is MD5:2c:c0:94:e8:3a:e4:74:88:c0:d8:e0:01:20:81:1d:8e. 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@172.16.75.1\'s password: Number of key(s) added: 1 Now try logging into the machine, with: ssh \'root@172.16.75.1\' and check to make sure that only the key(s) you wanted were added.
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持创新互联。