Explanation
Layer 4 is where TCP/IP port numbers identify which network application is receiving the packet and where it is applied. Layer 4 is also known as the transport layer in the TCP/IP model or the OSI model. The transport layer is responsible for providing reliable or unreliable end-to-end data transmission between hosts on a network. The transport layer uses port numbers to identify and multiplex different applications or processes that communicate over the network. Port numbers are 16-bit numbers that range from 0 to 65535 and are divided into three categories: well-known ports (0-1023), registered ports (1024-49151), and dynamic ports (49152-65535). Some examples of well-known port numbers are 80 for HTTP, 443 for HTTPS, and 25 for SMTP. References: [CompTIA Network+ Certification Exam Objectives], Transport Layer - an overview | ScienceDirect Topics

Explanation
According to troubleshooting methodology, after determining the most likely probable cause of an issue, the next step is to establish a plan of action to resolve the issue and identify potential effects. This step involves defining the steps needed to implement a solution, considering the possible consequences of each step, and obtaining approval from relevant stakeholders if necessary. References:
https://partners.comptia.org/docs/default-source/resources/comptia-network-n10-008-exam-objectives-(2-0),
https://www.comptia.org/blog/the-comptia-guide-to-it-troubleshooting

Explanation
SSID stands for Service Set Identifier and is the name of a wireless network. A wireless access point (WAP) can support multiple SSIDs, which allows different wireless access through the same equipment. For example, the store owner can create one SSID for business equipment and another SSID for patron use, and assign different security settings and bandwidth limits for each SSID. MIMO stands for Multiple Input Multiple Output and is a technology that uses multiple antennas to improve wireless performance. TKIP stands for Temporal Key Integrity Protocol and is an encryption method for wireless networks. LTE stands for Long Term Evolution and is a cellular network technology.
References: CompTIA Network+ Certification Exam Objectives Version 7.0 (N10-007), Objective 3.1: Given a scenario, install and configure wireless LAN infrastructure and implement the appropriate technologies in support of wireless capable devices.

Explanation
Port 23 should be blocked when checking firewall configuration to prevent outside users from telnetting into any of the servers at the datacenter. Port 23 is the default port for Telnet, which is an insecure protocol that allows remote access to servers and network devices. Telnet sends data in clear text, which can be easily intercepted and compromised by attackers. A more secure alternative is SSH, which uses port 22 and encrypts data. References:
https://www.cisco.com/c/en/us/support/docs/ip/routing-information-protocol-rip/13788-3.html

Explanation
Network security groups are cloud components that can filter inbound and outbound traffic between cloud resources based on rules and priorities. Network security groups can be applied to virtual machines, subnets, or network interfaces to control the network access and security. Network security groups can allow or deny traffic based on the source, destination, port, and protocol of the packets. Network security groups are different from NAT gateways, service endpoints, and virtual private clouds, which are other cloud components that have different functions and purposes.
References
1: Network Security Groups - N10-008 CompTIA Network+ : 3.2
2: CompTIA Network+ N10-008 Certification Study Guide, page 329-330
3: CompTIA Network+ N10-008 Exam Subnetting Quiz, question 17
4: CompTIA Network+ N10-008 Certification Practice Test, question 10