Quality of Service (QoS): This is a feature used in networking to prioritize certain types of traffic. By configuring QoS, network administrators can allocate higher bandwidth to time-sensitive applications like VoIP, video conferencing, or critical business applications during peak usage times. This helps to reduce latency and packet loss, which are often caused by congestion.
Load Balancing (A): While load balancing is useful in distributing traffic across multiple servers or paths, it does not address congestion on a single switch.
Port Mirroring (B): This is used for monitoring network traffic for troubleshooting and diagnostics but does not alleviate congestion.
Spanning Tree Protocol (D): STP prevents switching loops in redundant network topologies, but it is not designed to handle traffic prioritization or congestion issues.

The netstat command provides information about network connections, routing tables, interface statistics, masquerade connections, and multicast memberships. Running netstat on the server can help the administrator verify that the web server process is listening on the expected port (e.g., port 80 for HTTP or port 443 for HTTPS) and that there are no issues with network connections. This is a crucial first step in diagnosing why the web server is not accessible via a browser.
Reference: CompTIA Network+ study materials.

Band Steering: This technology enables wireless devices to connect to the most optimal frequency band (2.4 GHz or 5 GHz) by encouraging capable devices to switch to the less congested 5 GHz band. This improves overall network performance and prevents overcrowding on the 2.4 GHz band.
Wireless LAN controller (B): This manages multiple access points in a network but does not handle frequency optimization.
Directional antenna (C): This focuses the signal in a specific direction but does not affect frequency selection.
Autonomous access point (D): This operates independently but lacks advanced features like band steering.

Understanding ACLs:
Access Control Lists (ACLs): A set of rules used to control network traffic and restrict access to network resources by filtering packets based on IP addresses, protocols, or ports.
Implementing Security Zones:
Defining Zones: ACLs can be used to create security zones by applying specific rules to different departments, ensuring that only authorized traffic is allowed between these zones.
Control Traffic: ACLs control inbound and outbound traffic at network boundaries, enforcing security policies and preventing unauthorized access.
Comparison with Other Options:
Port Security: Limits the number of devices that can connect to a switch port, preventing MAC address flooding attacks, but not used for defining security zones.
Content Filtering: Blocks or allows access to specific content based on predefined policies, typically used for web filtering rather than network segmentation.
NAC (Network Access Control): Controls access to the network based on the security posture of devices but does not define security zones.
Implementation Steps:
Define ACL rules based on the requirements of each department.
Apply these rules to the appropriate network interfaces or firewall policies to segment the network into security zones.
Reference:
CompTIA Network+ study materials on network security and access control methods.