What three steps should you take to diagnose the problem?

A few days after JencoMart migrates the user credentials database to Google Cloud Platform and shuts down the old server, the new database server stops responding to SSH connections. It is still serving database requests to the application servers correctly.

What three steps should you take to diagnose the problem? Choose 3 answers.
A . Delete the virtual machine (VM) and disks and create a new one
B . Delete the instance, attach the disk to a new VM, and investigate
C . Take a snapshot of the disk and connect to a new machine to investigate
D . Check inbound firewall rules for the network the machine is connected to
E . Connect the machine to another network with very simple firewall rules and investigate
F . Print the Serial Console output for the instance for troubleshooting, activate the interactive console, and investigate

Answer: CDF

Explanation:

D: Handling "Unable to connect on port 22" error message

Possible causes include:

– There is no firewall rule allowing SSH access on the port. SSH access on port 22 is enabled on all Compute Engine instances by default. If you have disabled access, SSH from the Browser will not work. If you run sshd on a port other than 22, you need to enable the access to that port with a custom firewall rule.

– The firewall rule allowing SSH access is enabled, but is not configured to allow connections from GCP Console services. Source IP addresses for browser-based SSH sessions are dynamically allocated by GCP Console and can vary from session to session.

F: Handling "Could not connect, retrying…" error You can verify that the daemon is running by navigating to the serial console output page and looking for output lines prefixed with the accounts-from-metadata: string. If you are using a standard image but you do not see these output prefixes in the serial console output, the daemon might be stopped. Reboot the instance to restart the daemon.

References:

https://cloud.google.com/compute/docs/ssh-in-browser https://cloud.google.com/compute/docs/ssh-in-browser