CompTIA N10-009 Practice Test - Questions Answers

Introduction to OSI Model:

The OSI model is a conceptual framework used to understand network interactions in seven layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

Application Layer:

The application layer (Layer 7) is the topmost layer in the OSI model. It provides network services directly to end-user applications. This layer facilitates communication between software applications and lower layers of the network protocol stack.

Reliance on Other Layers:

The application layer relies on the transport layer (Layer 4) for data transfer across the network. The transport layer ensures reliable data delivery through protocols like TCP and UDP.

The network layer (Layer 3) is responsible for routing packets to their destination.

The data link layer (Layer 2) handles node-to-node data transfer and error detection.

The physical layer (Layer 1) deals with the physical connection between devices.

Explanation of the Options:

A . It relies upon other layers for packet delivery: This is correct. The application layer depends on the lower layers (transport, network, data link, and physical) for the actual delivery of data packets.

B . It checks independently for packet loss: This is incorrect. Packet loss detection is typically handled by the transport layer (e.g., TCP).

C . It encrypts data in transit: This is incorrect. Encryption is typically handled by the presentation layer or at the transport layer (e.g., TLS/SSL).

D . It performs address translation: This is incorrect. Address translation is performed by the network layer (e.g., NAT).

Conclusion:

The application layer's primary role is to interface with the end-user applications and ensure that data is correctly presented to the user. It relies on the underlying layers to manage the actual data transport and delivery processes.

CompTIA Network+ guide covering the OSI model and the specific roles and functions of each layer (see page Ref 10How to Use Cisco Packet Tracer).

Introduction to Subinterfaces:

Subinterfaces are logical interfaces created on a single physical interface. They are used to enable a router to support multiple networks on a single physical interface.

Use Case for Subinterfaces:

Subinterfaces are commonly used in scenarios where VLANs are implemented. A router with a single physical LAN port can be configured with multiple subinterfaces, each associated with a different VLAN.

This setup allows the router to route traffic between different VLANs.

Example Configuration:

Consider a router with a single physical interface GigabitEthernet0/0 and two VLANs, 10 and 20.

interface GigabitEthernet0/0.10

encapsulation dot1Q 10

ip address 192.168.10.1 255.255.255.0

!

interface GigabitEthernet0/0.20

encapsulation dot1Q 20

ip address 192.168.20.1 255.255.255.0

The encapsulation dot1Q command specifies the VLAN ID.

Explanation of the Options:

A . A router with only one available LAN port: This is correct. Subinterfaces allow a single physical interface to manage multiple networks, making it essential for routers with limited physical interfaces.

B . A firewall performing deep packet inspection: Firewalls can use subinterfaces, but it is not a requirement for deep packet inspection.

C . A hub utilizing jumbo frames: Hubs do not use subinterfaces as they operate at Layer 1 and do not manage IP addressing.

D . A switch using Spanning Tree Protocol: STP is a protocol for preventing loops in a network and does not require subinterfaces.

Conclusion:

Subinterfaces provide a practical solution for routing between multiple VLANs on a router with limited physical interfaces. They allow network administrators to optimize the use of available hardware resources efficiently.

CompTIA Network+ guide detailing VLAN configurations and the use of subinterfaces (see page Ref 9Basic Configuration Commands).

VLAN hopping is an attack where an attacker crafts packets with multiple VLAN tags, allowing them to traverse VLAN boundaries improperly. This can result in gaining unauthorized access to network segments that are supposed to be isolated. The other options do not involve the use of multiple network tags. MAC flooding aims to overwhelm a switch's MAC address table, DNS spoofing involves forging DNS responses, and ARP poisoning involves sending fake ARP messages.

According to the CompTIA Network+ course materials, VLAN hopping exploits the tagging mechanism in network packets to gain unauthorized access.

BGP (Border Gateway Protocol) is used for routing data between different ISPs, making it essential for the functioning of the internet. Its primary use is for exchanging routing information between autonomous systems, especially different ISPs. Preventing loops within a LAN is handled by protocols like Spanning Tree Protocol (STP), while improving reconvergence times and sharing routes with a Layer 3 switch are functions of other protocols or internal mechanisms.

The CompTIA Network+ training emphasizes BGP's role in the exchange of routing information across different ISPs and autonomous systems.

A CNAME (Canonical Name) record is used in DNS to alias one domain name to another. This means that newapplication.comptia.org can be made to resolve to the same IP address as www.comptia.org by creating a CNAME record pointing newapplication.comptia.org to www.comptia.org. SOA (Start of Authority) is used for DNS zone information, MX (Mail Exchange) is for mail server records, and NS (Name Server) is for specifying authoritative DNS servers.

The DNS section of the CompTIA Network+ materials describes the use of CNAME records for creating domain aliases.

A Virtual Private Cloud (VPC) is most closely associated with segmenting compute resources within a single cloud account. A VPC allows you to define a virtual network that closely resembles a traditional network, complete with subnets, route tables, and gateways. This segmentation enables the isolation of different parts of a network within a cloud environment, ensuring security and efficient resource management. VPCs are a key component in many cloud infrastructures, providing the flexibility to manage and control network settings and resources.

Reference: CompTIA Network+ Certification Exam Objectives - Cloud Models section.

The scenario describes a user connecting to a corporate VPN via a web browser using TLS to access an internal system. This setup is best described as a 'clientless' VPN. Clientless VPNs do not require a VPN client to be installed on the user's device; instead, they rely on a standard web browser to establish the connection. This method is particularly useful for providing secure, remote access to applications through a web interface without the need for additional software installations.

Reference: CompTIA Network+ Certification Exam Objectives - Remote Access Methods section.

To ensure that an IDS sees all packets without any loss and without introducing latency, the best approach is to use a port mirror, also known as a SPAN (Switched Port Analyzer) port. Port mirroring copies network packets seen on one switch port (or an entire VLAN) to another port where the IDS is connected. This method allows the IDS to monitor traffic passively without being in the direct path of network traffic, thus avoiding any additional latency.

Reference: CompTIA Network+ Certification Exam Objectives - Network Security section.

A patch panel is the best choice to facilitate a central termination point for all network cables on the floor of a company building. Patch panels are used to manage and organize multiple network cables, providing a central point where all cables converge. This setup allows for easy management, troubleshooting, and reconfiguration of network connections. The other options, such as UPS (Uninterruptible Power Supply), MDF (Main Distribution Frame), and rack, serve different purposes and are not specifically designed for the central termination of network cables.

Reference: CompTIA Network+ Certification Exam Objectives - Network Installation section.