ssh命令

这个文章nice，https://www.cnblogs.com/ftl1012/p/ssh.html

ssh，secure shell缩写，加密传输，比telnet明文传输更安全，旨在替代ftp和telnet链接linux服务器

默认端口22，服务器端包含ssh服务和sftp服务，客户端包含ssh链接命令和scp拷贝命令

scp每次都是全量拷贝，效率低，适合第一次拷贝，增量拷贝用rsync，能够双向拷贝

安装openssh，须要四个包：

    openssh-clients：客户端

    openssh-server：服务端

    openssh-askpass：密码诊断工具（能够不要）

    openssh：核心文件

    openssl：提供加密的程序

配置文件/etc/ssh/sshd_config

配置互信免密登录参考http://www.javashuo.com/article/p-owkljsya-mq.html

和别的服务同样能够stop start reload  restart

查看ssh端口

[hadoop@master ~]$ netstat -lntup | grep ssh 
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
[hadoop@master ~]$ sudo netstat -lntup | grep ssh 
[sudo] password for hadoop: 
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1247/sshd           
tcp6       0      0 :::22                   :::*                    LISTEN      1247/sshd           
[hadoop@master ~]$ sudo ss |grep ssh
tcp    ESTAB      0      0      192.168.168.11:ssh                  192.168.168.1:53026                
[hadoop@master ~]$ sudo netstat -a | grep ssh
tcp        0      0 0.0.0.0:ssh             0.0.0.0:*               LISTEN     
tcp        0      0 master:ssh              192.168.168.1:53273     ESTABLISHED
tcp        0      0 master:ssh              192.168.168.1:53026     ESTABLISHED
tcp6       0      0 [::]:ssh                [::]:*                  LISTEN     
[hadoop@master ~]$ sudo netstat -lnt | grep 22
tcp        0      0 192.168.122.1:53        0.0.0.0:*               LISTEN     
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN     
tcp6       0      0 :::22                   :::*                    LISTEN     
[hadoop@master ~]$ sudo netstat -lnt | grep ssh | wc -l
0
[hadoop@master ~]$ 

远程登录

ssh 192.168.168.12
ssh  root@192.168.168.12
ssh -X root@192.168.168.12
ssh 192.168.168.12  "ifconfig"
ssh omd@192.168.168.12 -t "sh /home/hadoop/test.sh"