My server is centos with a static public ip, and the gcloud firewall and built-in firewall allow all permissions. And some usuall ports like 80, 443, 8888 are working normally, but some like 20715, 20000 are not. Im been working long on this but can not find out the problem. Can u help me?
By default Google Cloud VPC Firewall does not allow all permissions. Did you change firewall rules to do it? You shouldn't. The correct way is to create a firewall rule that allows traffic on certain ports, in your case would be 20715 and 20000.
Running these commands inside the VM:
$ netstat -tlpn | grep 20715 $ netstat -tlpn | grep 20000
Should tell you if there is any program running on these ports. Check similar post.