Modules 4-7 Ethernet Concepts
What OSI physical layer term describes the capacity at which a medium can carry data?
Bandwidth
When the store-and-forward method of switching is in use, what part of the Ethernet frame is used to perform an error check?
CRC in the tráiler
What method is used to manage contention-based access on a wireless network?
CSMA/CA
Which data link layer media access control method does Ethernet use?
CSMA/CD
What is a characteristic of UTP cabling?
Cancellation
CSMA/CA
Carrier Sense Multiple Access/Collision Avoidance
CSMA/CD
Carrier Sense Multiple Access/Collision Detection
Which two functions are performed at the MAC sublayer of the OSI data link layer? (Choose two.)
Controls the NIC responsible for sending and receiving data on the physical medium and Integrates various physical technologies.
What OSI physical layer term describes the physical medium which uses electrical pulses?
Copper Cables
Which two devices commonly affect wireless networks? (Choose two.)
Cordless phones and microwaves
CRC
Cyclical Redundancy Check
What OSI physical layer term describes the physical medium that uses the propagation of light?
Fiber Optic Cable
FCS
Frame Check Sequence
Which three basic parts are common to all frame types supported by the data link layer? (Choose three.)
Header, data, and trailer
Which standards organization oversees development of wireless LAN standards?
IEEE
Which two statements are correct about IPv4 and IPv6 addresses? (Choose two.)
IPv6 addresses are represented by hexadecimal numbers and IPv4 addresses are 32 bits in length
Which two functions are performed at the MAC sublayer of the OSI data link layer? (Choose two.)
Implements a trailer to detect transmission errors and Controls the NIC responsible for sending and receiving data on the physical medium.
Which two functions are performed at the MAC sublayer of the OSI data link layer? (Choose two.)
Implements a trailer to detect transmission errors and Provides synchronization between source and target nodes.
Which statement correctly describes frame encoding?
It converts bits into a predefined code in order to provide a predictable pattern to help distinguish data bits from control bits.
What is the auto-MDIX feature?
It enables a device to automatically configure an interface to use a straight-through or a crossover cable.
What is one advantage of using fiber optic cabling rather than copper cabling?
It is able to carry signals much farther than copper cabling.
Which two functions or operations are performed by the MAC sublayer? (Choose two.)
It is responsible for Media Access Control and It adds a header and trailer to form an OSI Layer 2 PDU
Which two characteristics describe Ethernet technology? (Choose two.)
It is supported by IEEE 802.3 standards and It uses the CSMA/CD access control method
Which two statements describe the services provided by the data link layer? (Choose two.)
It manages the access of frames to the network media and It packages various Layer 3 PDUs into a frame format that is compatible with the network interface.
What is a characteristic of the LLC sublayer?
It places information in the frame allowing multiple Layer 3 protocols to use the same network interface and media
What are the two sublayers of the OSI model data link layer? (Choose two.)
LLC and MAC
What OSI physical layer term describes the amount of time, including delays, for data to travel from one point to another?
Latency
LLC
Logical Link Control
Which two statements describe features or functions of the logical link control sublayer in Ethernet standards? (Choose two.)
Logical link control is implemented in software and The data link layer uses LLC to communicate with the upper layers of the protocol suite.
What is the definition of bandwidth?
The amount of data that can flow from one place to another in a given amount of time
cut-through switching
The data packet is forwarded to the destination as soon as the destination MAC address has been read; cut through switching doesn't read the entire frame, just the MAC address. Low latency
A network administrator is designing a new network infrastructure that includes both wired and wireless connectivity. Under which situation would a wireless connection be recommended?
The end-user device needs mobility when connecting to the network.
fast-forward switching
a cut-through switching method that begins to forward data as soon as the destination address has been received
What is auto-MDIX?
a feature that detects Ethernet cable type
Store-and-Forward Switching
a switching method that receives the entire frame before forwarding
What type of communication rule would best describe CSMA/CD?
access method
Which switching method has the lowest level of latency?
fast-forward
Types of cut-through switching (two)
fast-forward and fragment-free
What type of cable is used to connect a workstation serial port to a Cisco router console port?
rollover
Which switching method uses the CRC value in a frame?
store-and-forward
Frame Forwarding Methods on Cisco Switching (Two)
store-and-forward and cut-through
Which frame forwarding method receives the entire frame and performs a CRC check to detect errors before forwarding the frame?
store-and-forward switching
What is the destination MAC address of the Ethernet frame as it leaves the web server if the final destination is PC1? (Has Graphic)
00-60-2F-3A-07-CC: The destination MAC address is used for local delivery of Ethernet frames. The MAC (Layer 2) address changes at each network segment along the path. As the frame leaves the web server, it will be delivered by using the MAC address of the default gateway.
What is the special value assigned to the first 24 bits of a multicast MAC address?
01-00-5E
How many bits are in an IPv4 address?
32
What are the two sizes (minimum and maximum) of an Ethernet frame? (Choose two.)
64 bytes and 1518 bytes
What type of address is 01-00-5E-0A-00-02?
an address that reaches a specific group of hosts
What type of physical topology can be created by connecting all Ethernet cables to a central device?
star
Which network device has the primary function to send data to a specific destination based on the information found in the MAC address table?
switch
Which network device makes forwarding decisions based on the destination MAC address that is contained in the frame?
switch
Desktop PCs in an enterprise office media
copper
Horizontal cabling structure media
copper
What is a primary role of the Physical layer in transmitting data on the network?
create the signals that represent the bits in each frame on to the media
Which characteristic describes crosstalk?
the distortion of the transmitted messages from signals carried in adjacent wires
Which layer of the OSI model is responsible for specifying the encapsulation method used for specific types of media?
Data Link
Which statement describes the half-duplex mode of data transmission?
Data that is transmitted over the network flows in one direction at a time.
What are two services performed by the data link layer of the OSI model? (Choose two.)
It accepts Layer 3 packets and encapsulates them into frames and It provides media access control and performs error detection.
Which function or operation is performed by the LLC sublayer?
It communicates with upper protocol layers.
What will a host on an Ethernet network do if it receives a frame with a destination MAC address that does not match its own MAC address?
It will discard the frame
What is true concerning physical and logical topologies?
Logical topologies refer to how a network transfers data between devices.
What attribute of a NIC would place it at the data link layer of the OSI model?
MAC address
Which statement is true about MAC addresses?
The first three bytes are used by the vendor assigned OUI.
What happens to runt frames received by a Cisco Ethernet switch?
The frame is dropped.
What statement describes a characteristic of MAC addresses?
They must be globally unique.
What does a router do after de-encapsulating a received frame?
determines the best path
fragment-free switching
frames forwarded once the header (first 64 bytes) is received and has no errors. Most errors are in first 64 bytes. Compromise between store and forward and cut-through
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?
mesh
What addressing information is recorded by a switch to build its MAC address table?
the source Layer 2 address of incoming frames
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
What is the purpose of the OSI physical layer?
transmitting bits across the local media
In addition to the cable length, what two factors could interfere with the communication carried over UTP cables? (Choose two.)
Crosstalk and electromagnetic interference
The PC is connected to the console port of the switch. All the other connections are made through FastEthernet links. Which types of UTP cables can be used to connect the devices?
1 - rollover, 2 - straight-through, 3 - crossover: A straight-through cable is commonly used to interconnect a host to a switch and a switch to a router. A crossover cable is used to interconnect similar devices together like switch to a switch, a host to a host, or a router to a router. If a switch has the MDIX capability, a crossover could be used to connect the switch to the router; however, that option is not available. A rollover cable is used to connect to a router or switch console port.
What is the binary representation for the decimal number 173?
10101101
How many binary bits exist within an IPv6 address?
128
Given the binary address of 11101100 00010001 00001100 00001010, which address does this represent in dotted decimal format?
236.17.12.10
What is the decimal equivalent of the hex number 0x3F?
63
Which two functions are performed at the LLC sublayer of the OSI data link layer? (Choose two.)
Adds Layer 2 control information to network protocol data and Places information in the frame that identifies which network layer protocol is being used for the frame.
Which two functions are performed at the LLC sublayer of the OSI data link layer? (Choose two.)
Adds Layer 2 control information to network protocol data.*Enables IPv4 and IPv6 to utilize the same network interface and media.
What OSI physical layer term describes the physical medium for microwave transmissions?
Air
Which statement is true about the CSMA/CD access method that is used in Ethernet?
All network devices must listen before transmitting
Which two functions are performed at the LLC sublayer of the OSI data link layer? (Choose two.)
Enables IPv4 and IPv6 to utilize the same network interface and media and Places information in the frame that identifies which network layer protocol is being used for the frame
Which two functions are performed at the LLC sublayer of the OSI data link layer? (Choose two.)
Enables IPv4 and IPv6 to utilize the same network interface and media and Adds Layer 2 control information to network protocol data.
Which statement describes an extended star topology?
End devices connect to a central intermediate device, which in turn connects to other central intermediate devices.
What are three ways that media access control is used in networking? (Choose three.)
Ethernet utilizes CSMA/CD, Media access control provides placement of data frames onto the media, and Data link layer protocols define the rules for access to different media.
Which is a multicast MAC address?
FF-FF-FF-FF-FF-FF 5C-26-0A-4B-19-3E 01-00-5E-00-00-03* 00-26-0F-4B-00-3E
Open the PT Activity. Perform the tasks in the activity instructions and then answer the question.Which port does Switch0 use to send frames to the host with the IPv4 address 10.1.1.5?
Fa0/11: Issuing the command ipconfig /all from the PC0 command prompt displays the IPv4 address and MAC address. When the IPv4 address 10.1.1.5 is pinged from PC0, the switch stores the source MAC address (from PC0) along with the port to which PC0 is connected. When the destination reply is received, the switch takes the destination MAC address and compares to MAC addresses stored in the MAC address table. Issuing the show mac-address-table on the PC0 Terminal application displays two dynamic MAC address entries. The MAC address and port entry that does not belong to PC0 must be the MAC address and port of the destination with the IPv4 address 10.1.1.5.
Which two fields or features does Ethernet examine to determine if a received frame is passed to the data link layer or discarded by the NIC? (Choose two.)
Frame Check Sequence and minimum frame size
What OSI physical layer term describes the measure of usable data transferred over a given period of time?
Goodput
Which two engineering organizations define open standards and protocols that apply to the data link layer? (Choose two.)
International Organization for Standardization (ISO) and International Telecommunication Union (ITU)
What are two characteristics of fiber-optic cable? (Choose two.)
It is not affected by EMI or RFI and It is more expensive than UTP cabling is.
What identifier is used at the data link layer to uniquely identify an Ethernet device?
MAC address
What OSI physical layer term describes the process by which one wave modifies another wave?
Modulation
Which two functions are performed at the MAC sublayer of the OSI data link layer? (Choose two.)
Provides a mechanism to allow multiple devices to communicate over a shared medium and Controls the NIC responsible for sending and receiving data on the physical medium.
Which two functions are performed at the MAC sublayer of the OSI data link layer? (Choose two.)
Provides synchronization between source and target nodes and Integrates various physical technologies.
What action will occur if a host receives a frame with a destination MAC address it does not recognize?
The host will discard the frame.
What action will occur if a host receives a frame with a destination MAC address of FF:FF:FF:FF:FF:FF?
The host will process the frame.* The host forwards the frame to the router. The host sends the frame to the switch to update the MAC address table. The host forwards the frame to all other hosts.
A network administrator is connecting two modern switches using a straight-through cable. The switches are new and have never been configured. Which three statements are correct about the final result of the connection? (Choose three.)
The link between the switches will work at the fastest speed that is supported by both switches, The link between switches will work as full-duplex., and The auto-MDIX feature will configure the interfaces eliminating the need for a crossover cable.
What is indicated by the term throughput?
The measure of the bits transferred across the media over a given period of time
A wireless LAN is being deployed inside the new one room office that is occupied by the park ranger. The office is located at the highest part of the national park. After network testing is complete, the technicians report that the wireless LAN signal is occasionally affected by some type of interference. What are two possible causes of the signal distortion? (Choose two.)
The microwave oven and the cellular phones that are used by the employees
During the encapsulation process, what occurs at the data link layer for a PC connected to an Ethernet network?
The physical address is added.
What action will occur if a switch receives a frame with the destination MAC address FF:FF:FF:FF:FF:FF?
The switch forwards it out all ports except the ingress port.
What action will occur if a switch receives a frame with the destination MAC address 01:00:5E:00:00:D9?
The switch forwards it out all ports except the ingress port.* The switch does not forward the frame. The switch sends the frame to a connected router because the destination MAC address is not local. The switch shares the MAC address table entry with any connected switches.
What action will occur if a switch receives a frame and does have the source MAC address in the MAC table?
The switch refreshes the timer on that entry.
Why are two strands of fiber used for a single fiber optic connection?
They allow for full-duplex connectivity.
What is contained in the trailer of a data-link frame?
They vary depending on protocols.
What OSI physical layer term describes the measure of the transfer of bits across a medium over a given period of time?
Throughput
Which IPv4 address format was created for ease of use by people and is expressed as 201.192.1.14?
dotted decimal
What three items are contained in an Ethernet header and trailer? (Choose three.)
source MAC address, destination MAC address, and error-checking information
What are two examples of the cut-through switching method? (Choose two.)
fast-forward switching and fragment-free switching
Backbone cabling in an enterprise media
fiber
Long haul networks media
fiber
Which advantage does the store-and-forward switching method have compared with the cut-through switching method?
frame error checking
Which media communication type does not require media arbitration in the data link layer?
full-duplex
What makes fiber preferable to copper cabling for interconnecting buildings? (Choose three.)
greater distances per cable run, limited susceptibility to EMI/RFI, and greater bandwidth potential
What is one advantage of using the cut-through switching method instead of the store-and-forward switching method?
has a lower latency appropriate for high-performance computing applications
What does the term "attenuation" mean in data communication?
loss of signal strength as distance increases
A network team is comparing physical WAN topologies for connecting remote sites to a headquarters building. Which topology provides high availability and connects some, but not all, remote sites?
partial mesh
A network administrator is troubleshooting connectivity issues on a server. Using a tester, the administrator notices that the signals generated by the server NIC are distorted and not usable. In which layer of the OSI model is the error categorized?
physical layer
Guest access in a coffee shop media
wireless
Waiting room in a hospital media
wireless
A Layer 2 switch is used to switch incoming frames from a 1000BASE-T port to a port connected to a 100Base-T network. Which method of memory buffering would work best for this task?
shared memory buffering
Which type of UTP cable is used to connect a PC to a switch port?
straight-through
A network administrator is measuring the transfer of bits across the company backbone for a mission critical financial application. The administrator notices that the network throughput appears lower than the bandwidth expected. Which three factors could influence the differences in throughput? (Choose three.)
the amount of traffic that is currently crossing the network, the type of traffic that is crossing the network and the latency that is created by the number of network devices that the data is crossing
What is the auto-MDIX feature on a switch?
the automatic configuration of an interface for a straight-through or a crossover Ethernet cable connection
With the use of unshielded twisted-pair copper wire in a network, what causes crosstalk within the cable pairs?
the magnetic field around the adjacent pairs of wire
What is the purpose of the FCS field in a frame?
to determine if errors occurred in the transmission and reception
What is the function of the CRC value that is found in the FCS field of a frame?
to verify the integrity of the received frame
Which procedure is used to reduce the effect of crosstalk in copper cables?
twisting opposing circuit wire pairs together
What are two actions performed by a Cisco switch? (Choose two.)
using the source MAC addresses of frames to build and maintain a MAC address table and utilizing the MAC address table to forward frames via the destination MAC address