CompTIA Network+ Practice Test (N10-009)

Anomaly alerting primarily functions to notify network administrators about unusual activities that deviate from normal operational metrics, allowing for timely investigation and response to potential problems. This helps in maintaining network security and performance by addressing issues before they escalate. Other options describe important aspects of network management, but they do not specifically relate to the proactive detection of deviations that anomaly alerting/notification provides.

Single-mode fiber is the optimal choice for long-distance and high-bandwidth applications as it uses laser light to send signals, which allows for smaller modal dispersion over long distances compared to multimode fiber and other types of cables. This makes it ideal for large-scale data centers that require high-speed data transfer across long distances without susceptibility to electrical interference. Multimode fiber, while also resistant to electrical interference and useful for moderate distances, cannot maintain signal quality over as long distances as single-mode. Coaxial and Twinaxial cables are susceptible to electromagnetic interference and are generally used for shorter distances.

DNS typically uses the connectionless UDP protocol on port 53 for standard name-resolution queries because its small, single-request/single-reply exchanges benefit from low overhead. When reliability is critical-such as during zone transfers or whenever a response exceeds 512 bytes-DNS switches to TCP on the same port to ensure ordered delivery and error recovery. The other options are incorrect because DNS does not rely exclusively on one protocol or reverse the protocol usage for these operations.

Optical fiber cable is the best choice for this environment because it transmits data using pulses of light, making it completely immune to electromagnetic interference (EMI) and radio frequency interference (RFI). Unshielded Twisted Pair (UTP) is highly susceptible to EMI. While Coaxial and Shielded Twisted Pair (STP) offer more protection against EMI than UTP, they are still copper-based and not fully immune. Therefore, optical fiber provides the most reliable performance in high-EMI environments.

The CompTIA troubleshooting methodology emphasizes identifying what has changed as an early step. A server update is a significant change that can alter various configurations. Host-based firewall rules are frequently modified during operating system or application updates to enhance security, which can inadvertently block legitimate traffic. Therefore, checking for changes in the firewall configuration is the most logical first step. While other options could potentially cause connectivity issues, they are less directly associated with a recent server update compared to a firewall rule modification.

For traditional WAN connections like T1 leased lines, serial interfaces are the correct choice. These interfaces are specifically designed for point-to-point links over long distances, which were common for technologies like T1. Ethernet interfaces are primarily used for Local Area Networks (LANs), although modern WAN services (often called Metro Ethernet) now use Ethernet over fiber. ISDN is an older WAN technology but is not typically used for a dedicated T1 line. Fiber Optic is a Layer 1 physical medium (the cable itself), not a Layer 2 interface type like Serial or Ethernet, which defines the communication protocol and connector.

TCP port 636 is reserved for LDAP over SSL/TLS (LDAPS). When a client connects to this port, the LDAP session is automatically encrypted with SSL or TLS before any directory queries or credentials are transmitted, protecting the confidentiality and integrity of the data. HTTPS instead uses port 443 for secure web traffic, multimedia messaging protocols use other ports, and secure file-transfer protocols use ports such as 22 (SFTP) or 989/990 (FTPS), so those options are incorrect.

Before installing any 6 GHz access points, administrators must confirm that both the infrastructure and client devices are certified for 6 GHz operation and that the intended power levels and indoor-only placement comply with local rules (for example, the FCC's low-power indoor restrictions and AFC requirements for higher power). If the hardware is not 6 GHz-capable-or if it is placed or powered outside the allowed regulatory envelope-the network will either fail to work for users or expose the organization to interference penalties. The other options mention settings (security mode, channel width, or legacy channel selection) that are not regulatory prerequisites for using the 6 GHz spectrum.

Checking the current bandwidth usage and availability is the correct first step because increased latency during peak hours often indicates that bandwidth is being saturated. By understanding the usage patterns and identifying any bandwidth-hungry applications, a technician can take steps to manage the load or potentially increase bandwidth to reduce congestion, thus decreasing latency. Configuring Quality of Service for prioritization might be necessary if the bandwidth is not sufficient, but first, the usage needs to be assessed. Upgrading firmware or inspecting the physical layer might not directly relate to solving a congestion-induced latency issue during peak hours without first confirming the root cause is due to bandwidth issues.

The Transport layer (Layer 4) is responsible for end-to-end communication management, including error correction and packet sequencing. It ensures reliable data transfer by managing flow control and providing mechanisms for error detection and recovery. The Session layer manages sessions between applications but does not handle error correction or sequencing. The Network layer deals with routing and logical addressing, focusing on data delivery across networks without ensuring reliability. The Data Link layer manages physical addressing and error detection for data frames on the same network segment but does not handle end-to-end error correction between hosts.

In a star topology, all nodes (computers, printers, etc.) are individually connected to a central networking device, such as a switch or hub, using a separate cable. This setup enhances fault tolerance, as the failure of a single cable only affects one node's connection to the network, not the entire network. The hub-and-spoke model is functionally the same as a star topology.

802.11ac, also known as Wi-Fi 5, operates exclusively in the 5 GHz frequency band. This band is typically less crowded than the 2.4 GHz band and allows for wider channels, enabling much higher data rates (up to several Gbps) that are ideal for bandwidth-intensive tasks like video conferencing and large file transfers. The 5 GHz frequency has a shorter effective range compared to 2.4 GHz, which aligns with the scenario's requirements. The other options are less suitable: 802.11b and 802.11g use the 2.4 GHz band and have significantly lower maximum speeds (11 Mbps and 54 Mbps, respectively). 802.11a uses the 5 GHz band but is an older standard with a maximum speed of only 54 Mbps.

Setting the MTU to match the smallest allowed data packet size in the network minimizes fragmentation. In settings with a combination of higher and lower capacity links, selecting the MTU of the smaller links as the standard avoids fragmentation that could occur if packets allowed by larger capacity links are too big to be handled by the smaller links without being broken up.

Single-mode fiber is the best choice for high-speed data-center backbones over long distances because it transmits a single light mode through an extremely small core using laser light, resulting in minimal signal loss and very high bandwidth across kilometers of fiber. Multimode fiber uses LEDs or VCSELs and supports only short- to medium-distance links (typically up to a few hundred meters) due to modal dispersion. Coaxial cable is largely obsolete for modern backbones, topping out at legacy 10 Mb/s speeds and shorter distances. Twinaxial cable (Direct-Attach Copper) is economical for very-short-reach links-usually under 7-10 m-but lacks the reach and low attenuation needed for backbone runs.

In a full tunnel configuration, all network traffic, regardless of its destination, is directed through the secured virtual tunnel. This differs significantly from a split tunnel, where only traffic intended for the internal network is routed through secure paths, and other traffic accesses the internet directly.