Free N10-009 Questions Attempt

A transceiver is the correct answer because it is the Layer 1 (Physical Layer) component that physically terminates and converts fiber-optic signals on an SFP-capable switch. In CompTIA Network+ N10-009 objectives, transceivers—such as SFP, SFP+, QSFP, and QSFP+ modules—are explicitly identified as physical interface components that handle signal transmission and reception. These modules convert electrical signals from the switch into optical signals for fiber cabling (and vice versa), enabling communication over different media types and distances.

A modem is also a Layer 1 device, but its purpose is to modulate and demodulate signals for WAN technologies such as DSL or cable—it does not terminate fiber connections on switches. An Ethernet NIC provides network access for end devices like computers and servers and typically terminates copper Ethernet, not modular fiber interfaces on switches. A repeater regenerates and amplifies signals to extend cable distances but does not provide fiber termination or media conversion at a switch port.

According to Network+ standards, SFP transceivers are essential for flexible network design, allowing administrators to select appropriate fiber types (single-mode or multi-mode), wavelengths, and distances while remaining compliant with physical layer requirements.

The best answer is C. Link aggregation. The requirements point directly to combining multiple physical links into one logical connection. Link aggregation provides higher total bandwidth, supports redundancy if one member link fails, and simplifies administration because the bundle is managed as a single logical interface instead of several separate ones.

Another important clue is vendor interoperability. Standards-based link aggregation, such as LACP, is designed to work across different vendors when supported properly. That makes it a strong match for inter-data-center switch environments where equipment may not all come from the same manufacturer.

The other choices do not satisfy the full requirement list. Spanning tree helps prevent loops, but it can block redundant links instead of actively using them for extra bandwidth. Setting interface speeds to 10GB increases speed per port, but it does not by itself provide the logical bundling, simplified management, or redundancy benefits described. Jumbo frames can improve efficiency for some traffic types, but they are not the right answer for bandwidth aggregation and resilient uplinks.

Because the question asks for a solution that improves throughput, keeps redundancy, remains cost effective, and is easier to manage, link aggregation is the strongest fit.

DHCP snooping is a security feature on network switches that helps to prevent unauthorized (rogue) DHCP servers from assigning IP addresses to clients. By implementing DHCP snooping, the network administrator can restrict DHCP responses to authorized servers only, preventing unauthorized DHCP configurations, such as incorrect DNS IPs, from being assigned to clients. This helps prevent man-in-the-middle attacks where malicious actors misconfigure DNS to redirect users to fraudulent sites. (Reference: CompTIA Network+ Study Guide, Chapter on Network Security)

Bandwidth is most likely affected during a successful denial-of-service attack. A DoS attack attempts to make a system, service, or network unavailable to legitimate users. One common method is flooding the target with excessive traffic, which consumes bandwidth, processing resources, or connection capacity. When bandwidth is overwhelmed, legitimate users may experience slow connections, dropped sessions, failed requests, or complete service unavailability.

The CompTIA Network+ N10-009 objectives include identifying common attacks and understanding their effect on network availability. DoS and DDoS attacks primarily target availability, one of the three core security goals in the CIA triad: confidentiality, integrity, and availability. Network-based DoS attacks often generate large amounts of traffic, making bandwidth a primary resource under attack.

A NAT pool could be exhausted in certain attack scenarios, but it is not the most general or most likely answer. An ACL is a rule set used to permit or deny traffic; it may help mitigate an attack but is not usually the resource being consumed. Storage availability could be affected in some application-specific attacks, but bandwidth is the best answer for a typical DoS attack.