Cannot access Google Cloud Compute Instance External IP

Question

I have set up an Google Cloud Compute Instance:

• Machine type
  • n1-standard-1 (1 vCPU, 3.75 GB memory)
• CPU platform
  • Intel Haswell
• Zone
  • us-east1-c

I can ssh in using the external address.

I have installed the vncserver and can access it on port 5901 from localhost as well as the internal IP.

I am trying to access it from the static, external IP address but it is not working.

I have configured the firewall to open to port to 0.0.0.0/0, but it is not reachable.

Can anyone help?

------after further investigation from the tips from the two answers (thanks, both!), I have a partial answer:

The Google Cloud Compute instance was set, by default, to not allow HTTP traffic. I reset the configuration to allow HTTP traffic. I then tried the troubleshooting tip to run a small HTTP service in python. I was able to get a ressponse from the service over the internet.

The summary of the current situation is as follows:

• The external IP address can be reached
• It is enabled and working for SSH
• It is enabled and working for HTTP
• It does not seem to allow traffic from vncserver

Any idea how to configure the compute instance to allow for vncserver traffic?

Answer 1

If you already verified that Google Firewall or your VM are not blocking packets, you must make sure that VNC service is configured to listen on the external IP address.

You can always use a utility like nmap outside Google project to reveal information on the port status.