What else will block the traffic to my Ubuntu instance?
SummaryCloud instance: UFW disabled but connection still being refused for port other than 22
I just created an Ubuntu-18.04 instance in the Oracle cloud. This instance is on the public subnet and it's assigned with a public IP of 140.238.63.xx. I didn't enable UFW firewall and also set None for the Network Security Group. In the Default Security list, which is the only Security List I have, I allowed all traffic to this machine on TCP port 2015 (Default Caddy service port) along with SSH port 22. I can SSH/ping to it remotely without any issue. However, I couldn't connect to it on TCP port 2015.