I created an Ampere Compute VM with Ubuntu 20.04, and default options everywhere. So I have a single cloud network with a single subnet with a single security list, all of which were created automatically when I created the instance.
I can ssh to it using the public IP, that's fine. However, I can't connect to it on any other port, from my home PC. For example I used netcat to listen to TCP 3389 on the server, but on my Windows desktop, "telnet <my-public-ip> 3389" waits, then eventually says "Connect failed". There's no response from the server.
Here's the output of some troubleshooting commands: http://paste.debian.net/plain/1220984
In case this link gets filtered, essentially:
1. netcat is listening properly on 3389
2. ufw is running and allowing 3389
3. tcpdump shows the connection requests are reaching the server, but no response from server
So this indicates a firewall issue, right? I tried disabling ufw, it had no effect.
I followed instructions on Cloud's Help page to add ingress rule for TCP 3389 to the security list prior to all this. It changed nothing. And the egress section has that default rule "allow all outgoing traffic" still there.
Unfortunately this is the extent of my knowledge, I don't know what to do here. I'm thinking Oracle Cloud VMs have some extra security rules beyond what a typical VPS does. Can anyone point me in the right direction?