220-1201 Practice Question: A company’s web server is accessible from the…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  The server’s default gateway is incorrect.

  Why it's wrong here

  The default gateway is the router's IP address that a device uses to send traffic to destinations outside its local subnet, including the internet. If the web server's default gateway were misconfigured, it would be unable to route any traffic to external networks or receive responses from internet clients. However, the problem states the server is accessible internally, indicating its basic network configuration for local communication is functional. The issue specifically preventing external access points to a problem at the network perimeter, not the server's fundamental routing capability.

• ✗

  A firewall rule on the server is blocking inbound traffic.

  Why it's wrong here

  A firewall rule configured directly on the web server to block inbound traffic on its service ports (e.g., TCP 80 or 443) would indeed prevent both internal and external users from accessing the service, unless very specific rules were in place to differentiate. Since the scenario explicitly states the server is accessible from the internal network, it implies that the server's local firewall is either configured to permit internal connections or is not the primary cause of the external access failure. This suggests the blockage occurs upstream at the network edge, before traffic even reaches the server's local firewall.

• ✓

  Port forwarding is not configured on the router.

  Why this is correct

  For a web server located on a private internal network behind a Network Address Translation (NAT) router, port forwarding is absolutely essential for external accessibility. This configuration instructs the router to listen for incoming connection requests on a specific public port (like 80 for HTTP or 443 for HTTPS) on its public IP address. It then translates and directs those requests to the web server's specific private IP address and corresponding port on the internal network. Without this crucial mapping, external requests attempting to reach the public IP address will not know which internal device to send the traffic to, effectively making the server unreachable from the internet despite being fully functional internally.

• ✗

  The DNS A record for the server points to the wrong IP.

  Why it's wrong here

  A DNS A record's purpose is to map a human-readable domain name (e.g., www.example.com) to a specific IP address. If this record were incorrect, users attempting to reach the server by its domain name would be directed to an invalid or unintended IP address, resulting in a name resolution failure. However, this issue primarily affects how clients find the server's public IP. Even if the DNS record correctly pointed to the router's public IP, the server would still be unreachable from the internet if port forwarding isn't configured, because the router wouldn't know where to direct the incoming traffic internally.

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