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.

• ✓

  MAC address

  Why this is correct

  Network switches operate at Layer 2 of the OSI model, utilizing Media Access Control (MAC) addresses to make forwarding decisions for frames within a local area network. A switch learns the MAC addresses of connected devices by examining the source MAC address of incoming frames and stores this information in its MAC address table (CAM table). When a frame arrives, the switch looks up the destination MAC address in this table to forward the frame out the correct port, ensuring efficient communication within the segment.

• ✗

  IP address

  Why it's wrong here

  IP addresses are logical network addresses used at Layer 3 (the Network Layer) of the OSI model to identify devices across different networks and facilitate routing. Standard network switches, however, are Layer 2 devices that operate solely on MAC addresses for forwarding frames within the same broadcast domain. While advanced Layer 3 switches can perform IP routing, a fundamental network switch does not inspect or use IP addresses for its primary frame forwarding function.

  When this WOULD be correct

  In a question about a router forwarding packets, the correct answer would be IP address. For example: 'A router forwards packets based on which address?'

• ✗

  Port number

  Why it's wrong here

  Port numbers are integral to Transport Layer (Layer 4) protocols like TCP and UDP, serving to identify specific applications or services running on a host. These numbers enable multiple applications on a single device to communicate simultaneously over the network. A network switch, operating at Layer 2, only examines the MAC address in the frame header and is entirely oblivious to the higher-layer port numbers, thus not using them for forwarding decisions.

  When this WOULD be correct

  A question asking 'Which criteria does a router use to forward packets?' would have port number as a correct answer if the question specifies 'when using network address translation (NAT) to map internal to external ports' or 'when applying access control lists (ACLs) based on port numbers'.

• ✗

  Domain name

  Why it's wrong here

  Domain names are human-readable identifiers, such as 'google.com', that are resolved to IP addresses by the Domain Name System (DNS). These names operate at the Application Layer (Layer 7) and are completely abstracted from the physical or data link layer operations of a network switch. Switches function exclusively at Layer 2 and therefore have no mechanism or need to interpret or utilize domain names for forwarding frames.

  When this WOULD be correct

  In a question about DNS resolution, such as 'Which service translates a domain name to an IP address?', domain name would be the correct answer as the input to a DNS query.

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?”