Connection refused on custom port on Azure linux VM

Question

I have a linux vm on Azure. I opened an inbound rule for port 20212 tcp and furthermore in created a rule in iptables to allow traffic to this port.

But when i do telnet 127.0.0.1 20212 i get a connection refused error and also when i do telnet SERVER-IP 20212 i get the same error. Is there any other step in need in opening a custom port on Azure VMs

Answer 1

There are 3 moving pieces to this puzzle:

1. Network Security Group allowing a port
2. Linux VM firewall allowing a port
3. Application that is running and listening on the port

It appears that you are missing the third one.