1.In this case, because you just wanted to open or close port 22960, a single command sufficed.
在这里，因为只希望打开或关闭端口22960，所以使用单一命令就够了。
2.Before starting knockd, close port 22960 and try to log in remotely.
在启动knockd之前，关闭端口22960并尝试远程登录。
3.You should also open the chosen port in your firewall and close port 22.
应该在防火墙上打开您选择的端口并关闭端口22。