Intro to Networks V7 -Chapter 6
Which of the following are data link layer protocols? (Choose three) 802.11 Ethernet IP PPP UDP
802.11 Ethernet PPP 802.11, Ethernet, and PPP are layer 2 protocols. IP is layer 3 and UDP is layer 4
What type of physical topology can be created by connecting all Ethernet cables to a central device? ring star mesh bus
star Topic 6.2.0 - Devices connected to the Ethernet star topology connect to either a hub or a switch.
What identifier is used at the data link layer to uniquely identify an Ethernet device? UDP port number TCP port number IP address sequence number MAC address
MAC address Topic 6.3.0 - Ethernet frames are identified at the data link layer by their MAC addresses, which are unique to each NIC. IP addresses are used at the network layer, and TCP and UDP port numbers are used at the transport layer. Sequence numbers are fields in TCP headers.
What is the function of the last field in a data link layer frame? To determine whether the frame experienced transmission errors To identify special flow control services such as quality of service (QoS) To identify the beginning and end limits of the frame To identify the Layer 3 protocol in the data field
To determine whether the frame experienced transmission errors The last field in the data link layer frame is the frame check sequence(FCS) which is used to determine if the frame has experienced transmission errors.
Which LAN topology is a hybrid topology? bus extended star ring star
extended star The extended star topology is considered hybrid topology because it combines multiple star topologies.
Which topology displays networking device layer IP addresses? aerial topology IP address topology logical topology physical topology
logical topology The logical topology shows the IP addresses assigned to device interfaces
What Layer 2 function does a router perform? (Choose three.) Accepts a frame from a medium De-encapsulates the frame Refers to its Layer 3 routing table for a matching destination network Re-encapsulates the packet into a new frame
Accepts a frame from a medium De-encapsulates the frame Re-encapsulates the packet into a new frame Routers perform 4 functions at Layer 2. 1. They accept a frame from media 2. de-encapsulate the packet from a frame 3. re-encapsulate the packet into a new frame 4. forwards the new frame appropriate to the medium of the segment of the physical network.
What method is used to manage contention-based access on a wireless network? token passing priority ordering CSMA/CD CSMA/CA
CSMA/CA Topic 6.2.0 - Carrier sense multiple access with collision avoidance (CSMA/CA) is used with wireless networking technology to mediate media contention. Carrier sense multiple access with collision detection (CSMA/CD) is used with wired Ethernet technology to mediate media contention. Priority ordering and token passing are not used (or not a method) for media access control.
Which data link layer media access control method does Ethernet use with legacy Ethernet hubs? determinism token passing CSMA/CD turn taking
CSMA/CD Topic 6.2.0 - CSMA/CD is used by Ethernet networks using legacy Ethernet hubs. CSMA/CA is used by 802.11-based wireless networks.
Which statement describes the half-duplex mode of data transmission? Data that is transmitted over the network can only flow in one direction. Data that is transmitted over the network flows in one direction at a time. Data that is transmitted over the network flows in one direction to many different destinations simultaneously. Data that is transmitted over the network flows in both directions at the same time.
Data that is transmitted over the network flows in one direction at a time. Topic 6.2.0 - The data that is transmitted over the network can flow using one of three modes: Simplex - Data can only flow in one direction. Half-duplex - Data flows in one direction at a time. Full-duplex - Data flows in both directions at the same time.
Which organization defines standards for the network access layer (i.e., the OSI physical and data link layers)? Cisco IANA IEEE IETF
IEEE The IEEE defines standards for the TCP/IP network access layer, which are the OSI physical and data link layers
Which two engineering organizations define open standards and protocols that apply to the data link layer? (Choose two.) Institute of Electrical and Electronics Engineers (IEEE) Internet Assigned Numbers Authority (IANA) International Telecommunication Union (ITU) Electronic Industries Alliance (EIA) Internet Society (ISOC)
Institute of Electrical and Electronics Engineers (IEEE) International Telecommunication Union (ITU) Topic 6.1.0 - The IANA is responsible for overseeing and managing IP address allocation, domain name management, and protocol identifiers. The EIA is an international standards and trade alliance for electronics organizations, and is best known for its standards related to electrical wiring, connectors, and the 19-inch racks used to mount networking equipment. IEEE defines open standards and protocols that apply to the network access layer.
What are two services performed by the data link layer of the OSI model? (Choose two.) It provides media access control and performs error detection. It monitors the Layer 2 communication by building a MAC address table. It accepts Layer 3 packets and encapsulates them into frames. It fragments data packets into the MTU size. It determines the path to forward packets.
It provides media access control and performs error detection. It accepts Layer 3 packets and encapsulates them into frames. Topic 6.1.0 - The data link layer is responsible for the exchange of frames between nodes over a physical network media. Specifically the data link layer performs two basic services: It accepts Layer 3 packets and encapsulates them into frames. It provides media access control and performs error detection. Path determination is a service provided at Layer 3. A Layer 2 switch builds a MAC address table as part of its operation, but path determination is not the service that is provided by the data link layer.
What is another name for the OSI data link layer? Layer 1 Layer 2 Layer 3 Layer 6
Layer 2 The data link layer is Layer 2 of the OSI model
The IEEE 802 LAN/MAN data link layer consists of which two sublayers? (Choose two.) Network Control Protocol Logical Link Control Media Access Control Link Control Protocol
Logical Link Control Media Access Control The data link layer consists of two sublayers. These are Logical Link Control (LLC) and Media Access Control (MAC)
What is true concerning physical and logical topologies? Logical topologies refer to how a network transfers data between devices. The logical topology is always the same as the physical topology. Physical topologies display the IP addressing scheme of each network. Physical topologies are concerned with how a network transfers frames.
Logical topologies refer to how a network transfers data between devices. Topic 6.2.0 - Physical topologies show the physical interconnection of devices. Logical topologies show the way the network will transfer data between connected nodes.
What are the two sublayers of the OSI model data link layer? (Choose two.) MAC physical transport internet network access LLC
MAC LLC Topic 6.1.0 - The data link layer of the OSI model is divided into two sublayers: the Media Access Control (MAC) sublayer and the Logical Link Control (LLC) sublayer.
What attribute of a NIC would place it at the data link layer of the OSI model? attached Ethernet cable RJ-45 port IP address MAC address TCP/IP protocol stack
MAC address Topic 6.3.0 - The data link layer describes media access and physical addressing. The encoding of a MAC address on a NIC places it at that layer. Ports and cables are placed at the physical layer of the OSI model. IP addresses are placed at the network layer. The TCP/IP protocol stack describes a different model.
The media access control method used depends on which two criteria? Layer 3 IP protocol Media sharing Topology Transport layer protocol Type of data
Media sharing Topology The two criteria for determining the media access control method used are they type of media sharing involved and the topology.
What is the responsibility of the MAC sublayer? Adds Layer 3 addresses to the frame Communicates with the network layer (Layer 3) Provides the method to get the frame on and off the media Transmits the bits on the media
Provides the method to get the frame on and off the media The MAC sublayer of the data link layer is responsible for getting frames on and off the media.
What kind of network would use point-to-point, hub and spoke, or mesh topologies? PAN LAN WLAN WAN
WAN Wide Area Networks(WANs) come in many topologies, to include point-to-point, hub and spoke, and mesh
Which media access control method is used in legacy Ethernet LANs? carrier sense multiple access/collision annoyance carrier sense multiple access/collision avoidance carrier sense multiple access/collision destruction carrier sense multiple access/collision detection
carrier sense multiple access/collision detection Carrier sense multiple access/collision detection (CSMA/CD) is the media access control method used in legacy Ethernet LANs.
Which layer of the OSI model is responsible for specifying the encapsulation method used for specific types of media? physical data link application transport
data link Topic 6.3.0 - Encapsulation is a function of the data link layer. Different media types require different data link layer encapsulation.
Which lists the Layer 2 and Layer 3 address fields in the correct order? destination NIC address, source NIC address, source IP address, destination IP address source NIC address, destination NIC address, source IP address, destination IP address destination NIC address, source NIC address, destination IP address, source IP address source NIC address, destination NIC address, destination IP address, source IP address
destination NIC address, source NIC address, source IP address, destination IP address This is the correct order of Layer 2 and Layer 3
Which duplex communication method is used in WLANs? full-duplex half-duplex simplex
half-duplex Wireless Lans (WLANs) only support half-duplex because only one device can access the media at a time.
What does the data link layer add to a Layer 3 packet to create a frame? (Choose two.) flags sequence number header trailer
header trailer The data link layer adds a header which contains the source and destination Layer 2 address and a trailer that contains a frame check sequence(FCS)
A technician has been asked to develop a physical topology for a network that provides a high level of redundancy. Which physical topology requires that every node is attached to every other node on the network? bus mesh star hierarchical ring
mesh Topic 6.2.0 - The mesh topology provides high availability because every node is connected to all other nodes. Mesh topologies can be found in WANs. A partial mesh topology can also be used where some, but not all, end points connect to one another.
Although CSMA/CD is still a feature of Ethernet, why is it no longer necessary? the use of Gigabit Ethernet speeds the use of full-duplex capable Layer 2 switches the use of CSMA/CA the development of half-duplex switch operation the virtually unlimited availability of IPv6 addresses
the use of full-duplex capable Layer 2 switches Topic 6.2.0 - The use of Layer 2 switches operating in full-duplex mode eliminates collisions, thereby eliminating the need for CSMA/CD.
Which is a function of the Logical Link Control (LLC) sublayer? to accept segments and package them into data units that are called packets to provide data link layer addressing to define the media access processes that are performed by the hardware to identify which network layer protocol is being used
to identify which network layer protocol is being used Topic 6.1.0 - Defining the media access processes that are performed by the hardware and providing data link layer addressing are functions of the MAC sublayer. The data link layer accepts Layer 3 packets and packages them into data units that are called frames.
