1、安装openssh

#yum install -y openssh

2、安装openssh-server

#yum install -y openssh-server

3、安装openssh-clients

#yum install -y openssh-clients

4、centos7 启动openssh

#systemctl start sshd.services

centos6 启动openssh

#/etc/init.d/sshd start

centos7 的启动没有/etc/init.d/sshd 只有 /etc/init.d/README

/etc/init.d/README 中描述了，cnetos7 要用systemctl 启动