Frank created a new virtual machine and tries to ping it, but the request times out. What is the most likely reason?

• A. ICMP is blocked at the firewall
• B. The VM has no public IP
• C. The VM is powered off
• D. The security group blocks HTTP

Answer: (A)

ICMP is the protocol behind the ping command. If the firewall or security group blocks ICMP, the Echo Request from your machine never gets a reply, so the result times out regardless of the VM’s actual uptime or IP configuration. In cloud environments, ICMP is often blocked by default to reduce exposure, and you must explicitly allow ICMP Echo and Echo Reply in the firewall or security group to enable ping.

The other possibilities are less likely to explain a timeout in this scenario: a VM with no public IP would prevent external ping from reaching it, but internal network ping to a private IP can still work; the VM being powered off would typically produce an immediate failure rather than a timed-out request; and blocking HTTP affects only TCP traffic on port 80, not ICMP, so ping would still timeout under that rule.

To resolve, enable ICMP in the firewall/security group for that VM and retry the ping.