How to open a specific port such as 9090 in Google Compute Engine

Question

I have 2 Google Compute Engine instances and I want to open port 9090 in both the instances. I think we need to add some firewall rules.

Can you tell me how can I

Answer 1

I had the same problem as you do and I could solve it by following @CarlosRojas instructions with a little difference. Instead of create a new firewall rule I edited the default-allow-internal one to accept traffic from anywhere since creating new rules didn't make any difference.