N10-009 Network Security 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.

• ✗

  VLAN

  Why it's wrong here

  A Virtual Local Area Network (VLAN) logically segments a network at Layer 2, separating broadcast domains and improving network organization. While a VLAN can isolate traffic between different internal departments or functions, it primarily focuses on logical separation rather than providing the robust security perimeter required for public-facing services. Without a dedicated firewall configuration to control inbound and outbound traffic specifically for public access, a VLAN alone does not offer the same level of security isolation as a DMZ for external users.

• ✓

  DMZ

  Why this is correct

  A Demilitarized Zone (DMZ) is a perimeter network specifically designed to host public-facing services, such as web servers or email servers, that need to be accessible from the internet. It acts as a buffer zone, typically situated between two firewalls: one separating it from the external internet and another separating it from the internal private network. This architecture allows external users to access specific services without gaining direct access to the sensitive internal network, significantly enhancing security by isolating potential threats.

• ✗

  VPN

  Why it's wrong here

  A Virtual Private Network (VPN) establishes an encrypted tunnel over an untrusted network, like the internet, to provide secure remote access for authorized users to a private network. While VPNs ensure data confidentiality and integrity for remote connections, they are not designed to host or isolate public-facing servers for general external access. Instead, a VPN grants specific authenticated users secure entry *into* a network, rather than securely exposing a service *from* a network to the broader public.

  When this WOULD be correct

  A question asking: 'A remote employee needs to securely access internal resources from a public Wi-Fi network. Which technology should be used?' In that scenario, a VPN is correct because it provides an encrypted connection to the internal network.

• ✗

  NAT

  Why it's wrong here

  Network Address Translation (NAT) is a method of remapping one IP address space into another, primarily used to allow multiple devices on a private network to share a single public IP address when accessing the internet. While NAT, specifically static NAT or port forwarding, can make an internal server accessible from the outside by translating its private IP to a public one, it does not inherently provide the crucial security isolation or segmented network architecture that a DMZ offers. NAT alone simply facilitates connectivity without creating a dedicated, hardened buffer zone.

  When this WOULD be correct

  A question asking how to allow multiple internal devices to share a single public IP address when accessing the internet, or how to hide internal IP addresses from external networks.

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?”