查看防火墙状态

sudo ufw status

[sudo] password for crf: 
Status: inactive

sudo ufw enable
Firewall is active and enabled on system startup

sudo ufw status

Status: active
To                         Action      From
--                         ------      ----
22                         ALLOW       Anywhere                  
22 (v6)                    ALLOW       Anywhere (v6)             

开放 80 端口

sudo ufw allow 80

Rule added
Rule added (v6)

开放 8080 端口

sudo ufw allow 8080
Rule added
Rule added (v6)

开放 22端口

sudo ufw allow 22
Skipping adding existing rule
Skipping adding existing rule (v6)

开启防火墙

sudo ufw enable

重启防火墙

sudo ufw reload

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