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 DNS server is not responding

  Why it's wrong here

  A non-responsive DNS server prevents a device from resolving human-readable hostnames into numerical IP addresses, which is crucial for accessing websites or network shares by name. Despite this, a DNS failure does not interfere with the DHCP process itself; the client would still successfully obtain a valid IP address, subnet mask, and default gateway. The device would retain its network connectivity and could still access resources directly by their IP addresses, just not by their names.

  When this WOULD be correct

  In a scenario where a user can access network resources by IP address but not by hostname, and the client has a valid DHCP-assigned IP address (not APIPA), the most likely cause is a DNS server not responding.

• ✓

  The DHCP server is unreachable

  Why this is correct

  When a client device fails to locate or communicate with a DHCP server, it cannot obtain a valid IP address, subnet mask, or default gateway from the network. In such scenarios, Windows operating systems automatically fall back to Automatic Private IP Addressing (APIPA), assigning itself an IP address in the 169.254.0.0/16 range. This link-local address prevents the device from communicating with any network resources beyond its immediate segment, directly causing the inability to access 'any' network services.

• ✗

  The default gateway is misconfigured

  Why it's wrong here

  A misconfigured default gateway primarily impacts a device's ability to route traffic to destinations outside its local subnet, such as the internet or other VLANs. However, the default gateway setting does not influence the process of obtaining an IP address from a DHCP server. The device would still successfully acquire a valid IP configuration, allowing it to communicate with other devices on its local segment, even if it cannot reach external networks.

  When this WOULD be correct

  A user can access local resources but cannot reach the internet. The ipconfig shows a valid IP, subnet mask, and default gateway. The correct answer would be that the default gateway is misconfigured or unreachable.

• ✗

  There is a duplicate IP address on the network

  Why it's wrong here

  A duplicate IP address on the network leads to an IP conflict, where two devices attempt to use the same unique identifier, causing intermittent connectivity issues and error messages for one or both systems. While disruptive, an IP conflict does not trigger the assignment of an APIPA address; the system would continue to attempt using its configured, albeit conflicting, IP address. APIPA is specifically a fallback mechanism for when a DHCP server cannot be reached to provide *any* IP configuration.

  When this WOULD be correct

  A user reports intermittent connectivity and an IP address conflict error message. The technician checks the DHCP server logs and finds no issues, but a ping to the user's IP from another workstation succeeds, indicating a duplicate IP address on the network.

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?”