Ali cloud server, the outer cover layer of security group; if the situation can not access the port appear, usually within a safe group setting
Among them, if you want to set the port segment, for all people, have access to all ip, ip addresses, we need to fill 0.0.0.0/0
If you want to limit access to a single IP, you need to fill 192.158.12.23/32, pay attention! ! ! Finally, behind the slash is 32