CCNA Networking Chapter 2 Quiz

A switch is considered an intermediary device because it acts as a bridge between multiple devices on a network. It receives data packets from one device and forwards them to the appropriate destination device based on the MAC addresses. Switches are commonly used in local area networks (LANs) to connect multiple devices, such as computers, printers, and servers, allowing them to communicate with each other efficiently. Unlike routers, which operate at the network layer, switches operate at the data link layer of the OSI model.

The network shown in the exhibit is a Local Area Network (LAN). A LAN is a network that covers a small geographical area, typically within a single building or campus. It connects devices such as computers, printers, and servers, allowing them to communicate and share resources. LANs are commonly used in homes, offices, schools, and other small-scale environments.

The term "intermediary" correctly identifies the device type that is included in area B. An intermediary device is a networking device that operates at the OSI model's layers 1-3 and is used to connect multiple devices together. It acts as a bridge or translator between different networks or segments, facilitating communication between devices. In this context, the device in area B is likely serving as a connection point between different networks or segments, making it an intermediary device.

The devices E, F, H, I, and J are considered end devices because they are the devices that directly interact with the network and are the source or destination of data. Devices A, B, C, D, and G are not considered end devices because they are either networking devices (A, B, C, D) or not directly connected to the network (G).

The OSI model is a conceptual framework used to understand and describe how different network protocols interact with each other. The proper order of the layers from highest to lowest is: application, presentation, session, transport, network, data link, physical. This order represents the flow of data from the application layer down to the physical layer, with each layer providing specific functions and services to the layer above it. The application layer is responsible for providing network services to user applications, while the physical layer deals with the actual transmission of data over the physical medium.

The exhibit shows three network segments labeled as Network A, Network B, and Network C. The correct labels for these network types are as follows:

- Network A is identified as a LAN (Local Area Network) because it represents a small geographical area, such as a home, office, or building.
- Network B is identified as a WAN (Wide Area Network) because it represents a larger geographical area, such as connecting multiple LANs across cities or countries.
- Network C is also identified as a LAN because it represents a small geographical area, similar to Network A.

Therefore, the correct labels for the network segments shown in the exhibit are Network A – LAN, Network B – WAN, and Network C – LAN.

The term that describes the data interleaving process represented in the graphic is multiplexing. Multiplexing is the technique of combining multiple data streams into a single stream for transmission over a shared medium. It allows multiple signals to share the same communication channel, increasing the efficiency and capacity of the network. In the exhibit, the graphic shows multiple data streams being combined into a single stream, indicating the use of multiplexing.

By examining the network layer header, one can identify the destination host address. The network layer header contains information about the source and destination IP addresses, which are used to identify the specific devices or hosts involved in the communication. This information is crucial for routing the data packets to the correct destination.

Based on the information provided in the exhibit, "Cell A" at IP address 10.0.0.34 has established an IP session with "IP Phone 1" at IP address 172.16.1.103. This indicates that "Cell A" is directly communicating with an end device, which is the IP Phone. Therefore, the best description for the function of wireless device "Cell A" is an end device.

A PDU, or Protocol Data Unit, refers to a layer-specific encapsulation. In computer networking, data is transmitted in the form of PDUs, which are structured units of information that are encapsulated at each layer of the network protocol stack. Each layer adds its own header to the PDU, containing control information specific to that layer. This encapsulation allows for the transmission of data across different layers of the network, ensuring that the data is properly handled and understood by the receiving device. Therefore, the correct answer is "a layer-specific encapsulation."

During the encapsulation process at the data link layer, the physical address is added. This layer is responsible for the transmission of data packets over the physical network. It adds a header to the data packet, which includes the physical address of the source and destination devices. This physical address, also known as the MAC address, is used by the data link layer to ensure that the data is delivered to the correct device on the network.

End devices in a network refer to devices that initiate or create data flow. They are the source of data transmission in a network, generating and sending data to other devices. These devices include computers, smartphones, tablets, printers, etc. They are responsible for initiating communication and sending information across the network.

A LAN is usually in a single geographical area, meaning it covers a small physical area such as a building or campus. The network is administered by a single organization, which means that one entity has control over the network and its management. A LAN provides network services and access to applications for users within a common organization, allowing users within the organization to connect and communicate with each other.

The network layer is responsible for encapsulating the segment into packets. This layer adds a header to the segment, which includes the necessary information such as source and destination IP addresses. The packets are then transmitted over the network to the destination. The network layer ensures that the packets are correctly routed to their destination by using routing protocols and determining the most efficient path.

Intermediary devices in a network play a crucial role in managing and facilitating the flow of data. They determine pathways for data by directing it to its intended destination, ensuring efficient and reliable transmission. They also retime and retransmit data signals, correcting any errors or delays that may occur during transmission. Additionally, intermediary devices manage data flows by controlling the rate at which data is sent and received, ensuring that it does not overwhelm the network. These three functions are essential for maintaining the smooth operation and optimal performance of a network.

The primary function of the trailer information added by the data link layer encapsulation is to support error detection. This trailer information contains a checksum or a cyclic redundancy check (CRC) value that allows the receiving device to verify if the data has been received correctly or if any errors have occurred during transmission. By detecting errors, the data link layer can request retransmission of the corrupted data, ensuring the integrity of the transmitted information.

The Network Access Layer in the TCP/IP model is responsible for the physical transmission of data over the network. It includes the Physical layer, which deals with the actual transmission of bits, and the Data Link layer, which handles the framing of data into frames and the detection and correction of transmission errors. Therefore, the Physical and Data Link layers in the OSI model have the same functions as the TCP/IP model Network Access Layer.

Encapsulation is a process in which data and its associated methods or functions are combined into a single unit called an object. It helps in organizing and managing data by grouping related variables and functions together. In the context of the given question, encapsulation allows the identification of pieces of data as part of the same communication, ensuring that they are treated as a cohesive unit. It also ensures that these data pieces can be directed to the correct receiving end device, enabling effective and accurate communication between devices.

The correct answer is to define the structure of layer-specific PDU's, outline the functions necessary for communications between layers, and require layer-dependent encapsulations. These statements accurately describe the role of network protocols. Network protocols define the structure of layer-specific Protocol Data Units (PDU's), which are used to encapsulate and transmit data between network layers. They also outline the functions necessary for communication between layers, ensuring that each layer performs its specific tasks. Additionally, network protocols often require layer-dependent encapsulations, meaning that each layer adds its own header and trailer to the data as it passes through the network stack. This helps ensure compatibility and proper functioning of the network.

Layer 4 port assignment is used to identify the processes or services that are communicating within the end devices. Layer 4 of the OSI model is the Transport layer, which is responsible for establishing connections, segmenting data, and ensuring reliable delivery of data between end devices. Port numbers are used at this layer to differentiate between different processes or services running on the same device. By assigning a unique port number to each process or service, the Transport layer can correctly deliver the data to the intended application on the receiving end device.

The purpose of the TCP/IP Network Access layer is network media control. This layer is responsible for managing the physical transmission of data over the network. It handles tasks such as encoding and decoding data into electrical or optical signals, as well as controlling access to the network media, such as Ethernet cables or wireless connections. This layer ensures that data is properly transmitted and received across the network media.