Networking Fundamentals - Modules 4-7
What are two examples of the cut-through switching method?
- fast-forward switching - fragment-free switching
Which frame forwarding method receives the entire frame and performs a CRC check to detect errors before forwarding the frame?
- store-and-forward switching
A network 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 difference in throughput?
- the amount of traffic that is currently crossing the network -the type of traffic that is crossing the network -the latency that is created by the number of devices that the data is crossing
What is the purpose of the FCS field in a frame?
- to determine if errors occurred in the transmission and reception
What are two action performed by 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
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
-01-00-5E-00-00-03
Which two functions are performed at the LLC sublayer of the OSI data link layer ?
-Adds Layer 2 control information to network protocol data. -Enables IPv4 and IPv6 to utilize the same network interface and media.
Which two functions are performed at LLC sublayer of the OSI data link layer?
-Adds Layer 2 control information to network protocol data. -Places information in the frame that identifies which network layer protocol is being used for the frame.
Which two functions are performed at the MAC sublayer of the OSI data link layer?
-Controls the NIC responsible for sending and receiving data on the physical medium. -Implements a trailer to detect transmission errors.
Which statement describes an extended star topology? -End devices connect to a central intermediate device, which in turn connects to other central intermediate devices. -End devices are connected together by a bus and each bus connects to a central intermediate device. -Each end system is connected to its respective neighbor via an intermediate -device. -All end and intermediate devices are connected in a chain to each other.
-End devices connect to a central intermediate device, which in turn connects to other central intermediate devices.
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? -CEF -Frame Check Sequence -minimum frame size -source MAC address
-Frame Check Sequence -minimum frame size
What are two characteristics of fiber-optic cable?
-It is not affected by EMI or RFI. -It is more expensive than UTP cabling is.
What describes the services provided by the data link layer?(choose two) -It defines the end-to-end delivery addressing scheme. -It manages the access of frames to the network media. -It ensures that application data will be transmitted according to the prioritization. -It packages various Layer 3 PDUs into a frame format that is compatible with the network interface.
-It manages the access of frames to the network media. -It packages various Layer 3 PDUs into a frame format that is compatible with the network interface.
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. -Logical link control is specified in the IEEE 802.3 standard. -The LLC sublayer adds a header and a trailer to the data. -The data link layer uses LLC to communicate with the upper layers of the protocol suite.
-Logical link control is implemented in software. -The data link layer uses LLC to communicate with the upper layers of the protocol suite.
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 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. -The auto-MDIX feature will configure the interfaces eliminating the need for a crossover cable.
Which tow devices commonly affect wireless networks?
-cordless phones -microwaves
In addition to the cable length, what two factors could interfere with the communication carried over UTP cables?
-crosstalk -electromagnetic interference
What are three ways the media access control is used in networking?
-ethernet utilizes CSMA/CD -media access control provides placement of data frame onto the media -data link layer protocols defines the rules for access to different media
What makes fiber preferable to copper cabling for interconnecting buildings?
-greater distances per cable run -limited susceptibility to EMI/RFI -greater bandwidth potential
Which three basic parts are common to all frame types supported by the data link layer? (Choose three.)
-header -data -trailer
A layer 2 switch is used to with incoming frames from a 1000BASE-T port to a port connected to a 100BASE-T network. Which method buffering would work best for this task? -port-based buffering -level 1 cache buffering -shared memory buffering -fixed configuration buffering
-shared memory buffering
What three items are contained in an Ethernet header and trailer?
-source MAC address -destination MAC address -error-checking information
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
Fiber optic supports higher bandwidth than UTP for longer distances. Fiber is immune to _______ and ________ but costs more, requires more skill to install, and requires more safety precautions
EMI & RFI
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 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.
Which type of UTP cable is used to connect a PC to a switch port?
Straight-through
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.
What is the purpose of the OSI physical layer?
Transmitting bits across the local media
What is crosstalk?
a type of noise, to interference that occurs when signals transmission on one wire interferes with another wire
What type of communication rule would best describe CSMA/CD?
access method
What OSI physical layer term describes the physical medium for microwave transmission?
air
Which statement Is true about the CSMA/CD access method that is used in Ethernet?
alll network devices must listen before transmitting
The appropriate use of network media for Fiber Optic
backbone cabling in an enterprise
What OSI physical layer term describes the capacity at which a medium can carry data?
bandwidth
What OSI physical layer term describes the physical medium which uses electrical pulses?
copper cable
What is the primary role of the physical layer in transmitting data on the network?
create signals that represents the bits in each frame on to the media
The appropriate use of network media for Copper Cables
desktop PCs in an enterprise office
What is contained in the trailer of the data-link frame?
error detection
Which switching method has the lowest level of latency?
fast-forward
What OSI physical layer term describes the physical medium that uses the propagation of light?
fiber-optic cable
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 OSI physical layer term describes the measure if usable data transferred over a given period of time?
good put
Another appropriate use of network media for Wireless
guess access in an coffee shop
What is one advantage of using cut-through switching method instead of the store-and-forwarding switching methods?
has a lower latency appropriate for high-performance computing applications
The appropriate use of network media for Copper Cables
horizontal cabling structure
What OSI physical layer term describes the amount of time, including delays, for data to travel from one point to another?
latency
Another appropriate use of network media for Fiber Optic
long- haul networks
What does the term "attenuation" mean in data communication?
loss of signal strength as distance increases
What OSI physical layer term describes the process by which one wave modifies another wave?
modulation
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
Which switching method uses the CRC value in a frame?
store-and-forward
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
Which characteristics describes crosstalk?
the distortion of the transmitted messages from signals carried in adjacent wires
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
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
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 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
Which statement describes a characteristic of the frame header fields of the data link layer?
they vary depending on protocols
What is the function of the CRC value that is found In the FCS field of the frame?
to verify the integrity of the receive frame
Which procedure is used to reduce the effect of crosstalk in copper cables?
twisting opposing circuits wires pairs together
The appropriate use of network media for Wireless
waiting rooms in a hospital
