1、使用usermod -L 选项限制用户登录
[root@linuxprobe home]# usermod -L linuxprobe ##禁止用户linuxprobe登录
[root@linuxprobe home]# passwd -S linuxprobe ## 查看状态，锁定状态
linuxprobe LK 2020-10-19 0 99999 7 -1 (Password locked.)
登录测试：
login as: linuxprobe ## 无法登录
linuxprobe@192.168.3.13's password:
Access denied
linuxprobe@192.168.3.13's password:
Access denied
linuxprobe@192.168.3.13's password:
使用usermod -U选项解除登录限制
[root@linuxprobe home]# passwd -S linuxprobe ## 解除登录限制
linuxprobe PS 2020-10-19 0 99999 7 -1 (Password set, SHA512 crypt.)
登录测试：
login as: linuxprobe ## 成功登录
linuxprobe@192.168.3.13's password:
Last failed login: Mon Oct 19 22:40:56 CST 2020 from 192.168.3.4 on ssh:notty
There were 4 failed login attempts since the last successful login.
Last login: Mon Oct 19 22:37:08 2020 from 192.168.3.4
2、使用passwd -l选项禁止用户登录
[root@linuxprobe home]# passwd -l linuxprobe ##禁止用户linuxprobe登录
Locking password for user linuxprobe.
passwd: Success
[root@linuxprobe home]# passwd -S linuxprobe ## 查看用户状态
linuxprobe LK 2020-10-19 0 99999 7 -1 (Password locked.)
登录测试：
login as: linuxprobe ## 无法登录
linuxprobe@192.168.3.13's password:
Access denied
linuxprobe@192.168.3.13's password:
Access denied
linuxprobe@192.168.3.13's password:
使用passwd -u选项接触登录限制
[root@linuxprobe home]# passwd -u linuxprobe ## 解除登录限制
Unlocking password for user linuxprobe.
passwd: Success
[root@linuxprobe home]# passwd -S linuxprobe ## 查看状态
linuxprobe PS 2020-10-19 0 99999 7 -1 (Password set, SHA512 crypt.)
登录测试：
login as: linuxprobe ## 可以登录
linuxprobe@192.168.3.13's password:
Last failed login: Mon Oct 19 22:48:14 CST 2020 from 192.168.3.4 on ssh:notty
There were 2 failed login attempts since the last successful login.
Last login: Mon Oct 19 22:44:25 2020 from 192.168.3.4