列出现有防火墙规则

以下Linux命令将列出所有当前使用的防火墙规则。

$ sudo ufw status numbered
Status: active
     To                         Action      From
     --                         ------      ---
[ 1] Apache Full                ALLOW IN    Anywhere                  
[ 2] OpenSSH                    ALLOW IN    Anywhere                  
[ 3] Apache Full (v6)           ALLOW IN    Anywhere (v6)             
[ 4] OpenSSH (v6)               ALLOW IN    Anywhere (v6)

删除防火墙规则

每个防火墙规则都以1到N编号为1.
使用相关的防火墙规则编号，我们可以选择性地删除任何给定规则。
例如：

$ sudo ufw delete 3
Deleting:
 allow 'Apache Full'
Proceed with operation (y|n)? y
Rule deleted (v6)

上面的命令将删除防火墙规则编号3.请注意，我们可以在此时删除一个规则。
每次更改时，规则编号都会发生变化：

$ sudo ufw status numbered
Status: active
     To                         Action      From
     --                         ------      ---
[ 1] Apache Full                ALLOW IN    Anywhere                  
[ 2] OpenSSH                    ALLOW IN    Anywhere                  
[ 3] OpenSSH (v6)               ALLOW IN    Anywhere (v6)