CompTIA Network+ Certification Exam N10-009 Practice Test 1

Which of the following terms refers to the OSI Network Layer?

• Layer 2

• Layer 5

• Layer 3

• Layer 4

Answer explanation

The OSI model has seven layers, and the Network Layer is specifically referred to as Layer 3. This layer is responsible for routing data packets between devices across different networks.

What type of equipment resides at Layer 1 of the OSI model? (Select all that apply)

• Router

• Hub

• Switch

• Network cabling

• Repeater

Answer explanation

Layer 1 of the OSI model includes physical equipment that transmits raw data. Hubs, network cabling, and repeaters are all physical devices that operate at this layer, while routers and switches operate at higher layers.

Examples of common protocols that reside at the OSI Transport Layer include: (Select 2 answers)

• UDP

• IP

• HTTPS

• ICMP

• TCP

Answer explanation

UDP and TCP are both protocols that operate at the OSI Transport Layer, responsible for end-to-end communication. IP operates at the Network Layer, while HTTPS is an application layer protocol, and ICMP is used for network diagnostics.

Which of the answers listed below refers to a unique, 48-bit identifier also known as physical network address?

• SSID

• IP

• GUID

• MAC

Answer explanation

The correct answer is MAC, which stands for Media Access Control. It is a unique, 48-bit identifier assigned to network interfaces for communications on the physical network, also known as a physical network address.

Which of the following devices reside(s) at the Data Link Layer of the OSI model? (Select all that apply)

• Bridge

• Media converter

• Switch

• Hub

• Network adapter

Answer explanation

The Data Link Layer includes devices that manage node-to-node data transfer. Bridges, switches, and network adapters operate at this layer, while media converters and hubs do not specifically function at the Data Link Layer.

The term "Presentation Layer" is used in reference to:

• Layer 7 of the OSI model

• Layer 5 of the OSI model

• Layer 6 of the OSI model

• Layer 4 of the OSI model

Answer explanation

The "Presentation Layer" refers to Layer 6 of the OSI model. It is responsible for data translation, encryption, and compression, ensuring that data is presented in a readable format for the application layer.

In the OSI model, the protocol data unit at the Physical Layer is known as:

• Segment

• Frame

• Bit

• Packet

• Datagram

Answer explanation

In the OSI model, the Physical Layer deals with the transmission of raw bits over a physical medium. Therefore, the protocol data unit at this layer is called a 'Bit', making it the correct answer.

Which OSI layer assumes the responsibility for opening, closing, and maintaining connections between applications?

• Network Layer

• Data Link Layer

• Application Layer

• Session Layer

Answer explanation

The Session Layer is responsible for opening, closing, and maintaining connections between applications, ensuring that sessions are established and managed effectively.

Which of the devices listed below is often referred to as a multilayer switch?

• Router

• Media converter

• Bridge

• Transceiver

Answer explanation

A router is often referred to as a multilayer switch because it operates at both Layer 2 (data link) and Layer 3 (network) of the OSI model, enabling it to perform switching and routing functions.

Which of the following protocols reside at the Application Layer of the OSI model? (Select 3 answers)

• ARP

• HTTP

• FTP

• IP

• SMTP

Answer explanation

HTTP, FTP, and SMTP are application layer protocols used for web browsing, file transfer, and email transmission, respectively. ARP operates at the Data Link Layer, and IP is at the Network Layer.