IT
Which of the following are data link layer protocols?
802.11, Ethernet, and PPP are Layer 2 protocols. IP is Layer 3 and UDP is Layer 4.
What is true concerning physical and logical topologies?
Physical topologies show the physical interconnection of devices. Logical topologies show the way the network will transfer data between connected nodes.
What Layer 2 function does a router perform?
Routers perform four functions at Layer 2. They accept a frame from the media, de-encapsulate the packet from a frame, re-encapsulate the packet into a new frame, and forwards the new frame appropriate to the medium of that segment of the physical network.
Which organization defines standards for the network access layer (i.e., the OSI physical and data link layers)?
The IEEE defines standards for the TCP/IP network access layer, which are the OSI physical and data link layers.
Which lists the Layer 2 and Layer 3 address fields in the correct order?
The correct order of Layer 2 and Layer 3 address fields is: destination NIC address, source NIC address, source IP address, destination IP address
What does the data link layer add to a Layer 3 packet to create a frame?
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).
The IEEE 802 LAN/MAN data link layer consists of which two sublayers?
The data link layer consists of two sublayers. These are Logical Link Control (LLC) and Media Access Control (MAC)
What is another name for the OSI data link layer?
The data link layer is Layer 2 of the OSI model.
What are the two sublayers of the OSI model data link layer?
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.
Which LAN topology is a hybrid topology?
The extended star topology is considered a hybrid topology because it combines multiple star topologies.
What is the function of the last field in a data link layer frame?
The last field in the data link frame is the frame check sequence (FCS) which is used to determine if the frame has experienced transmission errors.
Which topology displays networking device layer IP addresses?
The logical topology shows the IP addresses assigned to device interfaces.
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?
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.
The media access control method used depends on which two criteria?
The two criteria for determining the media access control method used are the type of media sharing involved and the topology.
Although CSMA/CD is still a feature of Ethernet, why is it no longer necessary?
The use of full duplex capable layer 2 switches
Which is a function of the Logical Link Control (LLC) sublayer?
To identify which network layer protocol is being used
Which statement describes the half-duplex mode of data transmission?
Which statement describes the half-duplex mode of data transmission?
What kind of network would use point-to-point, hub and spoke, or mesh topologies?
Wide Area Networks (WANs) come in many topologies, to include point-to-point, hub-and-spoke, and mesh.
Which duplex communication method is used in WLANs?
wireless LANs (WLANs) only support half-duplex because only one device can access the media at a time.
What is the responsibility of the MAC sublayer?
the MAC sublayer of the data link layer is responsible for getting frames on and off the media.
Which data link layer media access control method does Ethernet use with legacy Ethernet hubs?
CSMA/CD is used by Ethernet networks using legacy Ethernet hubs. CSMA/CA is used by 802.11-based wireless networks.
Which media access control method is used in legacy Ethernet LANs?
Carrier sense multiple access /collision detection (CSMA/CD) is the media access control method used in legacy Ethernet LANs.
What method is used to manage contention-based access on a wireless network?
Carrier sense multiple access with collision avoidance (CSMA/CA)
What type of physical topology can be created by connecting all Ethernet cables to a central device?
Devices connected to the Ethernet star topology connect to either a hub or a switch.
Which two engineering organizations define open standards and protocols that apply to the data link layer?
IEEE and ITU
What are two services performed by the data link layer of the OSI model?
It accepts Layer 3 packets and encapsulates them into frames. It provides media access control and performs error detection.
What identifier is used at the data link layer to uniquely identify an Ethernet device?
MAC address. 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 attribute of a NIC would place it at the data link layer of the OSI model?
MAC address. 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.
