Written Labs


In this section, you’ll complete the following labs to make sure you understand the information and concepts contained within them:

  • Lab 1.1: The OSI Reference Model

  • Lab 1.2: Defining the OSI Layers and Devices

  • Lab 1.3: Identifying Collision and Broadcast Domains

Lab 1.1: OSI Questions

Answer the following questions about the OSI model:

1.

Which layer chooses and determines the availability of communicating partners, along with the resources necessary to make the connection; coordinates partnering applications; and forms a consensus on procedures for controlling data integrity and error recovery?

the application layer is responsible for finding the network resources broadcast from a server and adding flow control and error control (if the application developer chooses).

2.

Which layer is responsible for converting data packets from the Data Link layer into electrical signals?

the physical layer takes frames from the data link layer and encodes the 1s and 0s into a digital signal from transmission on the network medium.

3.

At which layer is routing implemented, enabling connections and path selection between two end systems?

the network layer provides routing through an internetwork and through logical addressing.

4.

Which layer defines how data is formatted, presented, encoded, and converted for use on the network?

the presentation layer makes sure that data is in a readable format for the application layer.

5.

Which layer is responsible for creating, managing, and terminating sessions between applications?

the session layer sets up, maintains, and terminates sessions between applications.

6.

Which layer ensures the trustworthy transmission of data across a physical link and is primarily concerned with physical addressing, line discipline, network topology, error notification, ordered delivery of frames, and flow control?

pdus at the data link layer are called frames. as soon as you see frame in a question, you know the answer.

7.

Which layer is used for reliable communication between end nodes over the network and provides mechanisms for establishing, maintaining, and terminating virtual circuits; transport-fault detection and recovery; and controlling the flow of information?

the transport layer uses virtual circuits to create a reliable connection between two hosts.

8.

Which layer provides logical addressing that routers use for path determination?

the network layer provides logical addressing, typically ip addressing and routing.

9.

Which layer specifies voltage, wire speed, and pinout cables and moves bits between devices?

the physical layer is responsible for the electrical and mechanical connections between devices.

10.

Which layer combines bits into bytes and bytes into frames, uses MAC addressing, and provides error detection?

the data link layer is responsible for framing data packets.

11.

Which layer is responsible for keeping the data from different applications separate on the network?

the session layer creates sessions between different hosts applications.

12.

Which layer is represented by frames?

the data link layer frames packets received from the network layer.

13.

Which layer is represented by segments?

the transport layer segments user data.

14.

Which layer is represented by packets?

the network layer creates packets out of segments handed down from the transport layer.

15.

Which layer is represented by bits?

the physical layer is responsible for transporting 1s and 0s in a digital signal.

16.

Put the following in order of encapsulation:

  • Packets

  • Frames

  • Bits

  • Segments

segments, packets, frames, bits.

17.

Which layer segments and reassembles data into a data stream?

the transport layer segments and reassembles data into a data stream.

18.

Which layer provides the physical transmission of the data and handles error notification, network topology, and flow control?

the data link layer provides the physical transmission of the data and handles error notification, network topology, and flow control.

19.

Which layer manages device addressing, tracks the location of devices on the network, and determines the best way to move data?

the network layer manages device addressing, tracks the location of devices on the network, and determines the best way to move the data.

20.

What is the bit length and expression form of a MAC address?

48 bits (6 bytes) expressed as a hexadecimal number is the bit length and expression form of a mac address.

Answers

1.

The Application layer is responsible for finding the network resources broadcast from a server and adding flow control and error control (if the application developer chooses).

2.

The Physical layer takes frames from the Data Link layer and encodes the 1s and 0s into a digital signal from transmission on the network medium.

3.

The Network layer provides routing through an internetwork and through logical addressing.

4.

The Presentation layer makes sure that data is in a readable format for the Application layer.

5.

The Session layer sets up, maintains, and terminates sessions between applications.

6.

PDUs at the Data Link layer are called frames. As soon as you see “frame” in a question, you know the answer.

7.

The Transport layer uses virtual circuits to create a reliable connection between two hosts.

8.

The Network layer provides logical addressing, typically IP addressing and routing.

9.

The Physical layer is responsible for the electrical and mechanical connections between devices.

10.

The Data Link layer is responsible for framing data packets.

11.

The Session layer creates sessions between different hosts’ applications.

12.

The Data Link layer frames packets received from the Network layer.

13.

The Transport layer segments user data.

14.

The Network layer creates packets out of segments handed down from the Transport layer.

15.

The Physical layer is responsible for transporting 1s and 0s in a digital signal.

16.

Segments, packets, frames, bits.

17.

The Transport layer segments and reassembles data into a data stream.

18.

The Data Link layer provides the physical transmission of the data and handles error notification, network topology, and flow control.

19.

The Network layer manages device addressing, tracks the location of devices on the network, and determines the best way to move the data.

20.

48 bits (6 bytes) expressed as a hexadecimal number is the bit length and expression form of a MAC address.

Lab 1.2: Defining the OSI Layers and Devices

Fill in the blanks with the appropriate layer of the OSI reference model or hub, switch, or router device.

Description

Device or OSI Layer

This device sends and receives information about theNetwork layer.

This layer creates a virtual circuit for transmitting between two end stations.

This layer uses service access points.

This device uses hardware addresses to filter a network.

Ethernet is defined at these layers.

This layer supports flow control and sequencing.

This device can measure the distance to a remote network.

Logical addressing is used at this layer.

Hardware addresses are defined at this layer.

This device creates one big collision domain andonelarge broadcast domain.

This device creates many smaller collision domains, but the network is still one large broadcast domain.

This device breaks up collision domains and broadcast domains.

Answers to Lab 1.2

Description

Device or OSI Layer

This device sends and receives information about the Network layer.

router

This layer can create a virtual circuit for transmitting between two end stations.

Transport layer

This layer uses service access points.

Data Link layer (LLC sublayer)

This device uses hardware addresses to filter a network.

bridge or switch

Ethernet is defined at these layers.

Data Link and Physical layers

This layer supports flow control and sequencing.

Transport layer

This device can measure the distance to a remote network.

router

Logical addressing is used at this layer.

Network layer

Hardware addresses are defined at this layer.

Data Link layer (MAC sublayer)

This device creates one big collision domain and one large broadcast domain.

hub

This device creates many smaller collision domains but the network is still one large broadcast domain.

switch or bridge

This device breaks up collision domains and broadcast domains.

router

Lab 1.3: Identifying Collision and Broadcast Domains

1.

In Figure 1.24, identify the number of collision domains and broadcast domains in each specified device. Each device is represented by a letter.

  1. Hub

  2. Bridge

  3. Switch

  4. Router

    click to expand
    Figure 1.24: Identifying collision and broadcast domains

hub: one collision domain, one broadcast domain bridge: two collision domains, one broadcast domain switch: four collision domains, one broadcast domain router: three collision domains, three broadcast domains

Answers

1.

Hub: One collision domain, one broadcast domain

Bridge: Two collision domains, one broadcast domain

Switch: Four collision domains, one broadcast domain

Router: Three collision domains, three broadcast domains




CCDA. Cisco Certified Design Associate Study Guide
CCDA: Cisco Certified Design Associate Study Guide, 2nd Edition (640-861)
ISBN: 0782142001
EAN: 2147483647
Year: 2002
Pages: 201

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