4-7 Exam Review
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?
the amount of traffic that is currently crossing the network the type of traffic that is crossing the network the bandwidth of the WAN connection to the Internet
With the use of unshielded twisted-pair copper wire in a network, what causes crosstalk within the cable pairs?
the collision caused by two nodes trying to use the media simultaneously
Which is a multicast MAC address?
01-00-5E-00-00-03
What are three ways that media access control is used in networking?
Ethernet utilizes CSMA/CD. Data link layer protocols define the rules for access to different media. Media access control provides placement of data frames onto the 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.
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 trailer.
In addition to the cable length, what two factors could interfere with the communication carried over UTP cables?
Crosstalk and electromagnetic interference
Which two functions are performed at the LLC sublayer of the OSI data link layer?
Enables IPv4 and IPv6 to utilize the same network interface and media. Adds Layer 2 control information to network protocol data.
Which switching method has the lowest level of latency?
Fast-Forward
What are two examples of the cut-through switching method?
Fragment-free switching Fast-forward switching
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 is the primary role of the Physical layer in transmitting data on the network?
It creates the signals that represent the bits in each frame onto the media.
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 are two characteristics of a fiber-optic cable?
It is more expensive than UTP cabling. It is not affected by EMI or RFI.
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
What is contained in the trailer of a data link frame?
Physical address
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 switching method uses the CRC value in a frame?
Store-and-forward
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?
The auto-MDIX feature will configure the interfaces eliminating the need for a crossover cable. 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.
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 and does have the source MAC address in the MAC table?
The switch refreshes the timer on that entry.
Which statement describes a characteristic of the frame header fields of the data link layer?
They vary depending on protocols.
What three items are contained in an Ethernet header and trailer?
destination MAC address source MAC address error-checking information
What makes fiber preferable to copper cabling for interconnecting buildings?
greater distances per cable run greater bandwidth potential limited susceptibility to EMI/RFI
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 are two actions performed by a Cisco switch?
using the source MAC addresses of frames to build and maintain a MAC address table utilizing the MAC address table to forward frames via the destination MAC address
