In CenOS 7 systems, OpenSSH server is a system tray openssh, openssh-server packages provide a (installed by default), and has been added as a standard system sshd service, you can do systemctl status sshd to view services status. As long as a valid login shell, without considering security restrictions, you can telnet operating system.
sshd default service profile located / etc / ssh under / sshd_config directory, many of the configuration item to this control connection server. It can be divided into three areas:
Monitor service options:
[root@localhost /]# vim /etc/ssh/sshd_config
Port 22 // 端口号 ， 默认为 22
ListenAddress 192.168.1.10 // 监听地址，默认监听所有地址
protocol 2 // 使用 SSH V2 协议
........ // 省略
UseDNS no // 禁用 DNS 反向解析
........ // 省略User login control:
[root@localhost /]# vim /etc/ssh/sshd_config
LoginGraceTime 2m // 登录验证时间为 2 分钟
PermitRootLogin no // 禁止 root 用户登录
MaxAuthTries 6 // 最大重试次数为 6
PermitEmptyPasswords no // 禁止空密码用户登录Login authentication mode:
[root@localhost /]# vim /etc/ssh/sshd_config
PasswordAuthentication yes #启用密码验证
PubkeyAuthentication yes #启用密钥对验证
AuthorizedKeysFile .ssh/authorized_keys #指定公钥库文件Recommended:
[root@localhost /]# vim /etc/ssh/sshd_config
Port 2345 #监听端口为2345，不使用默认的端口
ListenAddress 172.16.2.25 #监听某一个IP地址 ，而不是监听所有IP地址
protocol 2 #使用SSH V2协议，比V1安全性更高
UseDNS no #禁用DNS反向解析
LoginGraceTime 2m #登录验证时间为2分钟
PermitRootLogin no #禁止root用户登录
MaxAuthTries 6 #最大重试次数为6
PermitEmptyPasswords no #禁止空密码登录
PasswordAuthentication yes #启用密码验证
PubkeyAuthentication yes #启用密钥对验证
AuthorizedKeysFile .ssh/authorized_keys #指定公钥库文件
AllowUsers zhangsan [email protected] #仅允许zhangsan和admin远程登录到
#该服务器，并且admin只能从192.168.2.10这个主机登录到该服务器。
#AllowUsers表示仅允许；与之相反的还有DenyUsers：表示仅拒绝。这两个配置项不允许同时出现ssh remote login:
[root@localhost ~]# ssh -p 2345 [email protected] #以用户zhangsan连接到192.168.1.10
# “-p”选项用来指定端口号为2345，若端口号为默认的22，那么-p选项可省略。
The authenticity of host '192.168.1.1 (192.168.1.1)' can't be established.
ECDSA key fingerprint is ad:a1:9b:f7:e3:41:bf:5f:da:cd:5e:3f:74:e0:8a:b9.
Are you sure you want to continue connecting (yes/no)? yes #“yes”
Warning: Permanently added '192.168.1.1' (ECDSA) to the list of known hosts.
[email protected]'s password: # 输入用户zhangsan的密码
[zhangsan@localhost ~]$ # 连接成功scp remote replication:
If the remote target is not the default port number, you need to add "-P" option to specify the port number
Upload:
[root@localhost /]# scp -r /a.txt [email protected]:/tmp
#将本地/a.txt 文件上传到远程主机“/tmp”目录下
[email protected]'s password: #输入1.10主机的root密码
passwd 100% 2893 2.8KB/s 00:00 #上传成功download:
[root@localhost /]# scp [email protected]:/b.txt /root/ #将1.10主机的文件下载到本地
[email protected]'s password:
b.txt 100% 20 0.0KB/s 00:00