Networking Basics Module 5 – 7 Checkpoint Exam Answers
1. Which two OSI model layers have the same functionality as two layers of the TCP/IP model? (Choose two.)
- data link
Explanation: The OSI transport layer is functionally equivalent to the TCP/IP transport layer, and the OSI network layer is equivalent to the TCP/IP Internet layer. The OSI data link and physical layers together are equivalent to the TCP/IP network access layer. The OSI session layer (with the presentation layer) is included within the TCP/IP application layer.
2. Which three acronyms/initialisms represent standards organizations? (Choose three.)
Explanation: TCP/IP is a protocol stack that contains a lot of other protocols such as HTTP, FTP, and DNS. The TCP/IP protocol stack is required to be used when communicating on the Internet. A MAC address is an address that is burned into an Ethernet network card. OSI is the 7 layer model that is used to explain how networking works.
3. Match the TCP/IP model layer to the function.
Explanation: Place the options in the following order:
||determines the best path to forward data through the network.
||represents data to the user, data encoding, and dialog control.
||controls hardware devices and media that make up the network.
||supports communication between diverse devices across networks.
4. Which statement defines a data communications protocol?
- an alliance of network device manufacturers
- a set of rules that govern the communication process
- an exchange agreement of network devices among vendors
- a set of product standards for types of network devices
Explanation: A data communication protocol is a set of rules that govern the communication process.
5. Which statement is true about the TCP/IP and OSI models?
- The first three OSI layers describe general services that are also provided by the TCP/IP internet layer.
- The OSI Layer 7 and the TCP/IP application layer provide identical functions.
- The TCP/IP network access layer has similar functions to the OSI network layer.
- The TCP/IP transport layer and OSI Layer 4 provide similar services and functions.
Explanation: The TCP/IP internet layer provides the same function as the OSI network layer. The transport layer of both the TCP/IP and OSI models provides the same function. The TCP/IP application layer includes the same functions as OSI Layers 5, 6, and 7.
6. Which three layers of the OSI model map to the application layer of the TCP/IP model? (Choose three.)
- data link
Explanation: The TCP/IP model consists of four layers: application, transport, internet, and network access. The OSI model consists of seven layers: application, presentation, session, transport, network, data link, and physical. The top three layers of the OSI model: application, presentation, and session map to the application layer of the TCP/IP model.
7. Which three elements do all communication methods have in common? (Choose three.)
- message priority
- message source
- message type
- message destination
- message data
- transmission medium
Explanation: All communication methods include a message source, destination, and a transmission medium.
8. What two characteristics describe an Ethernet cable? (Choose two.)
- 4 pairs of twisted cables
- plastic core surrounded by multiple layers for isolation and protection
- color coded pairs of cables
- single copper core surrounded by a layer of insulation
- glass core surrounded by multiple layers for isolation and protection
Explanation: In twisted-pair cables, wires are grouped in pairs and twisted together to reduce interference. The pairs of wires are colored so that the same wire at each end can be easily identified.
9. Which data encoding technology is used in fiber-optic cables?
- modulation of specific frequencies of electromagnetic waves
- modulation of electrical voltage
- electrical pulses
- pulses of light
Explanation: Data is transmitted across a network on media. Modern networks primarily use three types of media to interconnect devices:
- Metal wires within cables (copper cable, such as twisted-pair and coaxial cable) – Data is encoded into electrical impulses.
- Glass or plastic fibers within cables (fiber-optic cable) – Data is encoded into pulses of light.
- Wireless transmission – Data is encoded via modulation of specific frequencies of electromagnetic waves.
10. What is one advantage of using fiber optic cabling rather than copper cabling?
- It is able to be installed around sharp bends.
- It is easier to terminate and install than copper cabling.
- It is able to carry signals much farther than copper cabling.
- It is usually cheaper than copper cabling.
Explanation: Copper cabling is usually cheaper and easier to install than fiber optic cabling. However, fiber cables generally have a much greater signaling range than copper.
11. Which type of network cable is commonly used in backbone networks and telephone companies?
- twisted-pair cable
- shielded twisted-pair cable
- fiber-optic cable
- coaxial cable
Explanation: Fiber-optic cables can carry very large amounts of data and are used extensively by telephone companies and in backbone networks.
12. Which two applications are suitable for deploying coaxial cables? (Choose two.)
- to connect network devices in backbone networks
- to connect data centers with high bandwidth requirements over long distances
- to connect PC computers in an office
- to connect various components in a satellite communication system
- to connect a TV set to the wall plug at home
Explanation: Coaxial cable is the kind of copper cable used by cable TV companies. It is used to connect TV sets to the wall jacks that are connected to a cable TV company. It is also used for connecting the various components which make up satellite communication systems.
13. Which criterion can be used to select the appropriate type of network media for a network?
- the types of data that need to be prioritized
- the number of intermediary devices that are installed in the network
- the cost of the end devices that are used in the network
- the environment where the selected medium is to be installed
Explanation: Criteria for choosing a network medium are the distance across which the selected medium can successfully carry a signal, the environment in which the selected medium is to be installed, the amount of data and the speed at which the data must be transmitted, and the cost of the medium and its installation.
14. Refer to the graphic. What type of cabling is shown?
- glass fiber-optic
- plastic fiber-optic
Explanation: Network cabling includes different types of cables:
- Twisted-pair Ethernet cables consist of four pairs of color-coded wires that have been twisted together and then encased in a flexible plastic sheath.
- Coaxial cables use a copper conductor and a layer of flexible plastic insulation that surrounds the copper conductor.
- Fiber-optic cables are flexible, extremely thin, transparent strands of glass surrounded by plastic insulation.
15. Which type of address does a switch use to build the MAC address table?
- source IP address
- destination IP address
- source MAC address
- destination MAC address
Explanation: When a switch receives a frame with a source MAC address that is not in the MAC address table, the switch will add that MAC address to the table and map that address to a specific port. Switches do not use IP addressing in the MAC address table.
16. Which term refers to the process of placing one message format inside another message format?
Explanation: Encapsulation is the process of placing one type of message format into another. On computer networks this process is known as encapsulation. Once a message is encapsulated, it is called a frame.
17. Refer to the exhibit. A PC with the MAC address of 0800.069d.3841 attached to port Fa0/8 is sending data to a device that has the MAC address of 6400.6a5a.6821. What will the switch do first to handle the data transfer?
- The switch will add the address 6400.6151.6821 to the MAC address table.
- The switch will send the frame to ports Fa0/4 and Fa0/6.
- The switch will add the address 0800.069d.3841 to the MAC address table.
- The switch will send the frame to port Fa0/6.
- The switch will flood the frame out all ports except port Fa0/8.
Explanation: Every frame that enters a switch is checked for new information to learn. It does this by examining the source MAC address of the frame and port number where the frame entered the switch:
If the source MAC address does not exist in the MAC address table, the MAC address and incoming port number are added to the table.
18. Refer to the exhibit. How is a frame sent from PCA forwarded to PCC if the MAC address table on switch SW1 is empty?
- SW1 forwards the frame directly to SW2. SW2 floods the frame to all ports connected to SW2, excluding the port through which the frame entered the switch.
- SW1 floods the frame on all ports on the switch, excluding the interconnected port to switch SW2 and the port through which the frame entered the switch.
- SW1 drops the frame because it does not know the destination MAC address.
- SW1 floods the frame on all ports on SW1, excluding the port through which the frame entered the switch.
Explanation: When a switch powers on, the MAC address table is empty. The switch builds the MAC address table by examining the source MAC address of incoming frames. The switch forwards based on the destination MAC address found in the frame header. If a switch has no entries in the MAC address table or if the destination MAC address is not in the switch table, the switch will forward the frame out all ports except the port that brought the frame into the switch.
19. What are two actions performed by a Cisco switch? (Choose two.)
- utilizing the MAC address table to forward frames via the destination MAC address
- building a routing table that is based on the first IP address in the frame header
- using the source MAC addresses of frames to build and maintain a MAC address table
- forwarding frames with unknown destination IP addresses to the default gateway
- examining the destination MAC address to add new entries to the MAC address table
Explanation: Important actions that a switch performs are as follows:
– When a frame comes in, the switch examines the Layer 2 source address to build and maintain the Layer 2 MAC address table.
– It examines the Layer 2 destination address to determine how to forward the frame. When the destination address is in the MAC address table, then the frame is sent out a particular port. When the address is unknown, the frame is sent to all ports that have devices connected to that network.
20. Which information does a switch use to populate the MAC address table?
- the source and destination MAC addresses and the incoming port
- the source MAC address and the incoming port
- the source and destination MAC addresses and the outgoing port
- the destination MAC address and the incoming port
- the destination MAC address and the outgoing port
- the source MAC address and the outgoing port
Explanation: To maintain the MAC address table, the switch uses the source MAC address of the incoming packets and the port that the packets enter. The destination address is used to select the outgoing port.
21. How much data can be encapsulated into a normal sized Ethernet frame before it is sent over the network?
- 64 to 1518 bytes
- 0 to 1024 bytes
- 46 to 1500 bytes
- 32 to 1500 bytes
Explanation: According to the Ethernet standards, each Ethernet frame can carry 46 to 1500 bytes of user data. During the encapsulation process, other fields are added, such as destination MAC address, source MAC address, and FCS. The size of Ethernet frames is normally limited to a maximum of 1518 bytes and a minimum of 64 bytes.