Modules 4-7 Exam
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
Minimum Frame Size
64 bytes
Shielded Twisted Pair (STP)
A twisted pair cable that has an aluminum shield inside the plastic jacket that surrounds the pairs of wires.
Switching that begins to forward a frame after reading the destination MAC address
Fast forward
What OSI physical layer term describes the physical medium that uses the propagation of light?
Fiber-optic Cable
Switching that reads the first 64 bytes of a frame before forwarding
Fragment-free
Which media communication type does not require media arbitration in the data link layer?
Full-Duplex
What OSI physical layer term describes the measure of usable data transferred over a given period of time?
Goodput
What three items are contained in an Ethernet header and trailer?
Header: •source and destination MAC Addresses Trailer: •error-checking information
What action will occur if a switch receives a frame with the destination MAC address 01:00:5E:00:00:D9?
The switch will forward it out all ports except the ingress port
Which statement describes a characteristic of the frame header fields of the data link layer?
They vary depending on protocols.
What OSI physical layer term describes the measure of the transfer of bits across a medium over a greater period of time?
Throughput
When to use a straight-through cable
Unlike devices
What is contained in the trailer of a data-link frame?
error detection (CRC)
Which switching method has the lowest level of latency?
fast forward
Which advantage does the store-and-forward switching method have, compared with the cut-through switching method?
frame error checking
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
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 special value do Multicast MAC addresses begin with?
01-00-5E-00-00-03
Which statement describes an extended start topology?
End devices connect to a central intermediate device, which in turn connects to other central intermediate devices
When to use a crossover cable
Like devices
Ingress Port
Where the data came from
What is the purpose of the FCS field in the frame?
to determine if errors occurred in the transmission and reception
Which two statements describes features or functions of the logical link control sublayer in Ethernet standards?
•Logical Link Control is implemented in software •The data link layer uses LLC to communicate with the upper layers of the protocol suite
Data Link Layer has 2 sub layers
•Media Access Control (MAC) •Logical Link Control (LLC)
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
Fiber Optic
•backbone cabling in an enterprise •long-haul networks
In addition to the cable length, what two factors could interfere with the communication carried over UTP cables?
•crosstalk •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 •places information in the frame that identifies with network layer protocol is being used for the frame •Adds Layer 2 control information to network protocol data
What are two examples of the cut-through switching method?
•fast-forward switching •fragment-free switching
What makes fiber preferable to copper cabling for interconnecting buildings? (Choose three.)
•greater distances per cable run •limited susceptibility to EMI/RFI •greater bandwidth potential
Wireless
•guest access in a coffee shop •waiting rooms in a hospital
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 a primary role of the Physical layer in transmitting data on the network?
Create the signals that represent the bits in each frame on the media
Shared Memory Buffering
Deposits all frames into a common memory buffer that all the ports on the switch share.
Broadcast MAC Address
FF-FF-FF-FF-FF-FF
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 OSI physical layer term describes the amount of time, including delays, for data to travel from one point to another?
Latency
What does the term "attenuation" mean in data communication?
Loss of signal strength as distance increases
Unshielded Twisted Pair (UTP)
Networking cable that has four twisted pairs of copper wire and a flexible outer coating.
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 is the function of the Cyclic Redundancy Check (CRC) value that is found in the Frame trailer (FCS) field of a frame?
Verifies the integrity of the received frame
What type of communication rule would best describe CSMA/CD?
access method (Half-duplex)
What OSI physical layer term describes the process by which one wave modified another wave?
modulation
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
Which frame forwarding method receives the entire frame and performs a CRC check to detect errors before forwarding the frame?
store-and-forward switching
Which statement is true about the CSMA/CD access method that is used in Ethernet?
•All network devices must listen before transmitting
What are three ways that media access control is used in networking?
•Ethernet uses CSMA/CD •Media access control provides placement of data frames onto the media •Data link protocols define the rules to access different media
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?
•Frame Check Sequence (FCS) •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 three basic parts are common to all frame types supported by the data link layer?
•header •trailer •data
Copper Cables
•horizontal cabling structure •desktop PCs in an enterprise office
Which two functions are performed at the MAC sublayer of the OSI data link layer?
•implements a trailer to detect transmission errors •Controls the NIC responsible for sending and receiving data on the physical medium •provides a mechanism to allow multiple devices to communicate over a shared medium •integrates various physical technologies •provides synchronization between sources and target nodes
Which two statements describes the services provided by the data link layer?
•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 interfaces
Which two devices commonly affect wireless networks?
•microwaves •cordless phones
Which three factors can 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 latency that is created by the number of network devices that the data is crossing
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 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 •utilizing the MAC address table to forward frames via the destination MAC address
Rollover Cable
A Cisco proprietary cable used to connect a computer system to a router or switch console port.
Carrier Sense Multiple Access with Collision Detection (CSMA/CD)
A media access method in which a device must first listen (carrier sense) to the medium to be sure no other device is transmitting. If two devices transmit at the same time (multiple access), a collision occurs and is detected (collision detection). In this case, all devices involved in the collision wait for a random period of time before transmitting again.
What OSI physical layer term describes the physical medium for microwave transmissions?
Air
What action will occur if a switch receives a frame with the destination MAC address FF:FF:FF:FF:FF:FF(broadcast)?
The switch forwards it out all ports except the ingress port
