N10-009 Networking Concepts 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.

• ✗

  Makes forwarding decisions based on IP addresses

  Why it's wrong here

  IP addresses function at the Network Layer (Layer 3) of the OSI model, providing logical addressing for routing across different networks. A standard Layer 2 switch, however, operates exclusively at the Data Link Layer, inspecting only the MAC addresses within the frame header. It lacks the internal architecture and processing capabilities to interpret IP packet headers or make forwarding decisions based on IP addresses, which is a function reserved for routers or Layer 3 switches.

  When this WOULD be correct

  This option would be correct for a question asking about a characteristic of a Layer 3 switch or a router, which makes forwarding decisions based on IP addresses.

• ✓

  Uses MAC addresses to make forwarding decisions

  Why this is correct

  A Layer 2 network switch operates at the Data Link Layer, using Media Access Control (MAC) addresses for intelligent frame forwarding. It dynamically builds a MAC address table (CAM table) by learning the source MAC addresses of incoming frames and associating them with specific ports. When a frame arrives, the switch inspects its destination MAC address and consults the CAM table to forward the frame only to the corresponding output port, effectively segmenting collision domains and enhancing network efficiency.

• ✗

  Can route traffic between different VLANs without a router

  Why it's wrong here

  VLANs segment a single physical network into multiple logical broadcast domains at Layer 2. To enable communication between devices residing in different VLANs, traffic must traverse a Layer 3 device capable of routing, such as a router or a Layer 3 switch. A pure Layer 2 switch only forwards frames within the same VLAN based on MAC addresses and cannot perform inter-VLAN routing, as it lacks the necessary Layer 3 intelligence to interpret IP addresses and route packets between distinct subnets.

  When this WOULD be correct

  In a question about a multilayer switch that supports both switching and routing, or if the question specifies a Layer 3 switch with routing capabilities enabled, then it can route traffic between VLANs without an external router.

• ✗

  Provides Network Address Translation (NAT)

  Why it's wrong here

  Network Address Translation (NAT) is a Layer 3 function that modifies IP addresses and port numbers in packet headers, typically used to allow multiple private IP addresses to share a single public IP address for internet access. A Layer 2 switch operates at the Data Link Layer and is designed for local frame forwarding, not for inspecting or altering IP packet headers. Therefore, it does not possess the functionality to perform NAT, which is a complex operation handled by devices like routers or firewalls.

  When this WOULD be correct

  A question asking 'Which device provides Network Address Translation (NAT) to allow multiple devices to share a single public IP address?' would have NAT as the correct answer, typically a router or firewall.

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?”