centos7.6解决FirewallD is not running问题

1.查看firewalld状态:systemctl status firewalld，如果是dead状态，即防火墙未开启。

[root@instance-06qq0w7c ssh]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)

2.开启防火墙systemctl start firewalld
3.确认firewalld状态:systemctl status firewalld

[root@instance-06qq0w7c ssh]# systemctl start firewalld
[root@instance-06qq0w7c ssh]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: active (running) since Fri 2022-01-28 11:25:39 CST; 1min 58s ago
     Docs: man:firewalld(1)
 Main PID: 2559 (firewalld)
   CGroup: /system.slice/firewalld.service
           └─2559 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid

Jan 28 11:25:39 instance-06qq0w7c systemd[1]: Starting firewalld - dynamic....
Jan 28 11:25:39 instance-06qq0w7c systemd[1]: Started firewalld - dynamic ....
Hint: Some lines were ellipsized, use -l to show in full.

4.向防火墙添加端口号，出现success表示成功

Hint: Some lines were ellipsized, use -l to show in full.
[root@instance-06qq0w7c ssh]# firewall-cmd --zone=public --add-port=9527/tcp --permanent
success

5.关闭防火墙的指令：systemctl stop firewalld