On Linux, open, close, and view the firewall

After Alibaba Cloud sets up the security group, open the port number on the firewall on the Linux machine

open port

firewall-cmd --zone=public --add-port=8001/tcp --permanent

Restart the firewall:

firewall-cmd --reload

Query whether port number 8001 is open:

firewall-cmd --query-port=8001/tcp

Query which ports are open:

firewall-cmd --list-port

close port

firewall-cmd --zone=public --remove-port=8001/tcp --permanent