- (Topic 3)
A network engineer is upgrading an existing edge gateway. The company currently uses a router and needs to be able to filter on all OSI layers. Which of the following should the engineer
use to upgrade the gateway?

Correct Answer:A
A Next-Generation Firewall (NGFW) is a type of firewall that can filter traffic on all OSI layers, as well as provide advanced security features such as application awareness, intrusion prevention, and threat intelligence. A NGFW can replace a traditional router at the edge of a network and provide better protection against network attacks.
A proxy is a server that acts as an intermediary between clients and servers, forwarding requests and responses. A proxy can filter traffic on the application layer (layer 7), but not on the lower layers of the OSI model.
A layer 3 switch is a device that can perform both switching and routing functions. A layer 3 switch can filter traffic on the network layer (layer 3), but not on the higher or lower layers of the OSI model.
A load balancer is a device that distributes incoming traffic among a group of servers, improving performance and reliability. A load balancer can filter traffic on the transport layer (layer 4), but not on the higher or lower layers of the OSI model.
References
What is a Next-Generation Firewall?
What is a Reverse Proxy vs. Load Balancer?
Load Balancers Vs Api Gateway Vs Reverse Proxy
Reverse Proxy and Load Balancer: Understanding the Difference
CompTIA Network+ Certification All-in-One Exam Guide, Eighth Edition (Exam N10-008)

- (Topic 3)
A user calls the IT department to report being unable to log in after locking the computer The user resets the password, but later in the day the user is again unable to log in after locking the computer Which of the following attacks against the user IS MOST likely taking place?

Correct Answer:A

- (Topic 3)
A technician is investigating a misconfiguration on a Layer 3 switch. When the technician logs in and runs a command, the following data is shown:
Which of the following commands generated this output?

Correct Answer:C
The output shown in the image is from the show interface command, which displays information about the status and configuration of a network interface on a switch or router. The output includes the interface name, description, MAC address, IP address, speed, duplex mode, status, and statistics. The show route command displays the routing table of the device. The show config command displays the current configuration of the device. The tcpdump command captures and analyzes network traffic. The netstat -s command displays statistics for each protocol.
References: CompTIA Network+ Certification Exam Objectives Version 7.0 (N10-007), Objective 2.4: Given a scenario, use appropriate software tools to troubleshoot connectivity issues.

- (Topic 3)
A technician is working on a ticket for a user in the human resources department who received a new PC that does not connect to the internet. All users in human resources can access the
internet. The technician can ping the PC from the human resources router but not from the IT network. Which of the following is the most likely cause of the issue?

Correct Answer:D
An incorrect default gateway can cause a PC to not connect to the internet, because the default gateway is the device that routes traffic from the local network to other networks. If the PC has a wrong default gateway configured, it may not be able to reach the internet router or the IT network router. The technician can ping the PC from the human resources router because they are on the same local network, but not from the IT network router because they are on different networks.
A duplicate IP address can cause a PC to not communicate with other devices on the same network, because the IP address is the unique identifier of a device on a network. If two devices have the same IP address, they may cause IP conflicts and packet loss. However, a duplicate IP address would not prevent the technician from pinging the PC from the human resources router, because they are on the same network.
A misconfigured RIP can cause a router to not learn or advertise routes to other networks, because RIP is a routing protocol that dynamically exchanges routing information between routers. If a router has a wrong RIP configuration, it may not be able to reach or share routes with other routers. However, a misconfigured RIP would not affect the PC’s connectivity to the internet, because the PC does not use RIP.
An improper VLAN assignment can cause a PC to not communicate with other devices on the same or different networks, because a VLAN is a logical segmentation of a network that isolates traffic based on criteria such as function, security, or performance. If a PC is assigned to a wrong VLAN, it may not be able to access the resources or services that it needs. However, an improper VLAN assignment would not prevent the technician from pinging the PC from the human resources router, because they are on the same physical network.
References
What is a Default Gateway?
What’s an IP Conflict and How Do You Resolve It? What is RIP (Routing Information Protocol)?
What is a VLAN? How to Set Up a VLAN Network
CompTIA Network+ Certification All-in-One Exam Guide, Eighth Edition (Exam N10-008)

- (Topic 1)
Which of the following provides redundancy on a file server to ensure the server is still connected to a LAN even in the event of a port failure on a switch?

Correct Answer:A
NIC teaming, also known as network interface card teaming or link aggregation, allows multiple network interface cards to be grouped together to provide redundancy and increased throughput. In the event of a port failure on a switch, NIC teaming ensures that the file server remains connected to the LAN by automatically switching to another network interface card.
References: CompTIA Network+ Certification Study Guide, Sixth Edition by Glen E. Clarke

- (Topic 1)
A network engineer is investigating reports of poor network performance. Upon reviewing a report, the engineer finds that jitter at the office is greater than 10ms on the only WAN connection available. Which of the following would be MOST affected by this statistic?

Correct Answer:A
A VoIP sales call with a customer would be most affected by jitter greater than 10ms on the WAN connection. Jitter is the variation in delay of packets arriving at the destination. It can cause choppy or distorted audio quality for VoIP applications, especially over WAN links that have limited bandwidth and high latency. The recommended jitter for VoIP is less than 10ms. References: https://www.voip-info.org/voip-jitter/