Explanation
Shoulder surfing is the social engineering attack where an attacker watches a user log in to a corporate system and writes down the user's log-in credentials. Social engineering is a type of attack that exploits human psychology and behavior to manipulate or trick people into revealing sensitive information or performing malicious actions. Shoulder surfing is a form of social engineering that involves observing or eavesdropping on someone's screen, keyboard, or paper documents to obtain confidential information such as passwords, PINs, or credit card numbers. Shoulder surfing can be done in person or remotely using cameras or other devices. Shoulder surfing can be prevented by using privacy filters, locking screens, shielding keyboards, or being aware of one's surroundings. References: [CompTIA Network+ Certification Exam Objectives], What Is Shoulder Surfing? | Definition & Examples | Forcepoint

Explanation
The transceivers labeled 8Gbps are likely to be used with the Fibre Channel protocol. Fibre Channel is a high-speed networking technology that is primarily used to connect storage devices to servers in storage area networks (SANs). It is capable of transmitting data at speeds of up to 8 Gbps (gigabits per second), and uses specialized transceivers to transmit and receive data over fiber optic cables.
Coaxial over Ethernet (CoE) is a networking technology that uses coaxial cables to transmit data, and is not related to the transceivers in question. Internet Small Computer Systems Interface (iSCSI) is a protocol that allows devices to communicate over a network using the SCSI protocol, and does not typically use specialized transceivers. Gigabit interface converter (GBIC) is a type of transceiver used to transmit and receive data over fiber optic cables, but it is not capable of transmitting data at 8 Gbps.

Explanation
A network performance baseline is a set of metrics that represents the normal or expected behavior of a network under various conditions and scenarios. A network performance baseline can help a network administrator to investigate reports about network performance by comparing the current metrics with the historical metrics and identifying any deviations or anomalies. A network performance baseline can also help to plan and justify network upgrades by showing the trends and patterns of network utilization and performance over time.
A device configuration review is a process that involves checking and verifying the settings and parameters of a network device, such as a switch, router, firewall, or server. A device configuration review can help a network administrator to troubleshoot network issues by finding and fixing any errors, inconsistencies, or vulnerabilities in the device configuration. A device configuration review can also help to ensure compliance with security policies and best practices by applying the latest updates and patches to the device.
An ARP table export is a file that contains the contents of the ARP (Address Resolution Protocol) table of a network device. The ARP table is a data structure that maps IP addresses to MAC addresses on a local network. An ARP table export can help a network administrator to monitor and manage the network devices on a local network by showing their IP addresses and MAC addresses. An ARP table export can also help to detect and prevent ARP spoofing attacks by identifying any duplicate or malicious entries in the ARP table.
A service-level agreement (SLA) is a contract that defines the expectations and responsibilities of both parties in terms of service quality, availability, performance, and response time. An SLA can help a network administrator to provide and maintain a satisfactory level of service to the customers or users of the network by setting and measuring specific goals and metrics. An SLA can also help to resolve any disputes or issues that may arise between the service provider and the service consumer by establishing clear terms and conditions for the service delivery.

Explanation
A duplex mismatch is a situation where two devices on a network have different duplex settings, such as full-duplex or half-duplex. Full-duplex means that a device can send and receive data simultaneously, while half-duplex means that a device can only send or receive data at a time. A duplex mismatch can cause performance issues, such as collisions, errors, or slow throughput. In this scenario, the customer added a hub between the switch and the router. A hub is a device that operates at half-duplex and broadcasts all traffic to all ports. A switch and a router are devices that operate at full-duplex and forward traffic to specific ports.
Therefore, adding a hub between the switch and the router can cause a duplex mismatch and slow down all the other network components that were connected to the switch.
References: https://www.comparitech.com/net-admin/hub-vs-switch-vs-router/
https://www.cisco.com/c/en/us/support/docs/lan-switching/ethernet/10561-3.html

Explanation
The subnet mask is a binary value that defines how many bits of an IP address are used to identify the network and how many bits are used to identify the host. The subnet mask also determines the size and number of subnets in a network. The ipconfig command shows the current IP configuration of a device, including the subnet mask. In this case, the subnet mask is misconfigured because it does not match the network address of the device. The device has an IP address of 192.168.1.55, which belongs to the network 192.168.1.0/24 (with a subnet mask of 255.255.255.0). However, the subnet mask is set to 225.225.225.224, which is an invalid value that does not correspond to any network prefix length. This causes the device to be unable to communicate with other devices on the same network or access the default gateway. References: CompTIA Network+ N10-008 Certification Study Guide, page 109; The Official CompTIA Network+ Student Guide (Exam N10-008), page 5-4.