N10-009 Network Troubleshooting Practice Question

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 DHCP server is unreachable

  Why this is correct

  When a client fails to obtain an IP address from a DHCP server, it automatically assigns itself an Automatic Private IP Addressing (APIPA) address from the 169.254.0.0/16 range. This self-assigned address allows for limited local network communication but prevents connectivity to resources requiring a routable IP, such as a file server that might be on the same subnet but requires proper network configuration to be reached reliably. Therefore, an unreachable DHCP server directly leads to APIPA and the inability to connect.

• ✗

  The default gateway is misconfigured

  Why it's wrong here

  A misconfigured default gateway primarily impacts a client's ability to communicate with devices outside its local subnet. While it would prevent access to resources on different networks, it has no bearing on the client's initial IP address acquisition process. The client would still successfully obtain a valid IP address, subnet mask, and potentially DNS server information from a functional DHCP server, even if the gateway address provided was incorrect or unreachable.

• ✗

  The DNS server is down

  Why it's wrong here

  A DNS server's primary function is to resolve human-readable domain names into IP addresses. While critical for accessing resources by name, a DNS server's status does not influence the fundamental process of a client obtaining an IP address through DHCP. APIPA is a Layer 3 mechanism for IP address assignment when DHCP fails, completely unrelated to Layer 7 name resolution services. The client would still acquire an IP address, even if it couldn't resolve hostnames.

  When this WOULD be correct

  If a user reports 'cannot connect to a file server by name' but can connect by IP, and the IP configuration shows a valid IP address, then a DNS server issue is the likely cause.

• ✗

  The file server is offline

  Why it's wrong here

  The operational status of a file server, whether online or offline, is a service availability issue entirely independent of a client's IP address configuration. If the file server is offline, the client would still possess a valid IP address obtained from DHCP, allowing it to communicate with other network devices. The inability to connect would stem from the server's unavailability, not from the client's network interface self-assigning an APIPA address due to a DHCP failure.

  When this WOULD be correct

  In a scenario where a user reports 'cannot connect to a file server' and the technician verifies that the client has a valid IP address (e.g., 192.168.1.10) but cannot ping the file server by name or IP, the most likely cause would be that the file server is offline or its service is stopped.

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The N10-009 exam frequently reuses these exact scenarios with slightly different constraints.

Analysis generated from the official N10-009blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”