Networking Questions: Ethernet Concepts
What identifier is used at the data link layer to uniquely identify an Ethernet device?
MAC address
The media access control method used depends on which two criteria?
Media sharing; Topology
Which function or operation is performed by the LLC sublayer?
It communicates with upper protocol layers.
What kind of network would use point-to-point, hub and spoke, or mesh topologies?
WAN
True or false? The physical layer is only concerned with wired network connections.
false
True or false? When a frame is encoded by the physical layer, all bits are sent over the media at the same time.
false
What PDU is received by the physical layer for encoding and transmission?
frame
Which duplex communication method is used in WLANs?
half-duplex
What does the data link layer add to a Layer 3 packet to create a frame?
header; trailer
What is a characteristic of UTP cabling?
cancellation
Which LAN topology is a hybrid topology?
extended star
What is the dotted decimal representation of the IPv4 address 11001011.00000000.01110001.11010011?
203.0.113.211
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 special value assigned to the first 24 bits of a multicast MAC address transporting an IPv4 packet?
01-00-5E
Decimal to Hexadecimal Conversion Steps
1. Convert the decimal number to 8-bit binary strings. 2. Divide the binary strings in groups of four starting from the rightmost position. 3. Convert each four binary numbers into their equivalent hexadecimal digit.
Hexadecimal to Decimal Conversion Steps
1. Convert the hexadecimal number to 4-bit binary strings. 2. Create 8-bit binary grouping starting from the rightmost position. 3. Convert each 8-bit binary grouping into their equivalent decimal digit.
What is the dotted decimal representation of the IPv4 address which is represented as the binary string 00001010.01100100.00010101.00000001?
10.100.21.1
What is the binary representation for the decimal number 173?
10101101
What is the binary representation of 0xCA?
11001010
What is the binary equivalent of the decimal number 232?
11101000
Which of the following is the decimal equivalent of 7D?
125
How many binary bits exist within an IPv6 address?
128
What is the decimal equivalent of the binary number 10010101?
149
Which is the decimal equivalent of A9?
169
What is the decimal equivalent of 0xC9?
201
What Layer 2 function does a router perform? (Choose three.)
Accepts a frame from a medium; De-encapsulates the frame; Re-encapsulates the packet into a new frame
Which is the hexadecimal equivalent of 202?
CA
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 with legacy Ethernet hubs?
CSMA/CD
Which part of an Ethernet Frame uses a pad to increase the frame field to at least 64 bytes?
Data field
Which statement describes the half-duplex mode of data transmission?
Data that is transmitted over the network flows in one direction at a time
Which part of an Ethernet Frame describes the higher-layer protocol that is encapsulated?
EtherType
Which is the hexadecimal equivalent of 254?
FE
Which part of an Ethernet frame detects errors in the frame?
Frame Check Sequence
Which organization defines standards for the network access layer (i.e., the OSI physical and data link layers)?
IEEE
Which standards organization oversees development of wireless LAN standards?
IEEE
Which two statements are correct about IPv4 and IPv6 addresses?
IPv6 addresses are represented by hexadecimal numbers; IPv4 addresses are 32 bits in length
Which two functions or operations are performed by the MAC sublayer?
It adds a header and trailer to form an OSI Layer 2 PDU; It is responsible for Media Access Control
What is the definition of bandwidth?
It converts bits into a predefined code in order to provide a predictable pattern to help distinguish data bits from control bits.
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 characteristics describe Ethernet technology?
It is supported by IEEE 802.3 standards; It uses unique MAC addresses to ensure that data is sent to the appropriate destination.
What are the two sublayers of the OSI model data link layer?
LLC; MAC
Which part of an Ethernet Frame notifies the receiver to get ready for a new frame?
Preamble
What is the responsibility of the MAC sublayer?
Provides the method to get the frame on and off the media
Which of the following counters EMI and RFI by using shielding techniques and special connectors?
STP
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.
Why are two strands of fiber used for a single fiber optic connection?
They allow for full-duplex connectivity.
What statement describes a characteristic of MAC Addresses?
They must be globally unique
Logical Link Control (LLC)
This IEEE 802.2 sublayer communicates between the networking software at the upper layers and the device hardware at the lower layers. It places information in the frame that identifies which network layer protocol is being used for the frame. This information allows multiple Layer 3 protocols, such as IPv4 and IPv6, to use the same network interface and media.
What is the function of the last field in a data link layer frame?
To determine whether the frame experienced transmission errors
Which of the following wireless standards is best suited for industrial and IoT environments?
Zigbee
What is auto-MDIX?
a feature that detects Ethernet cable type
What type of address is 01-00-5E-0A-00-02?
an address that reaches a specific group of hosts
What feature automatically negotiates the best speed and duplex setting between interconnecting devices?
autonegotiation
Which of the following wireless standards is used for Personal Area Networks (PANs) and allows devices to communicate over distances of 1 to 100 meters?
bluetooth
Which media access control method is used in legacy Ethernet LANs?
carrier sense multiple access/collision detection
Which of the following attaches antennas to wireless devices? It can also be bundled with fiber-optic cabling for two-way data transmission.
coaxial
Which of the following terminates with BNC, N type and F type connectors?
coaxial
What is a function of the MAC sublayer?
controls access to the media; checks for errors in received bits; uses CSMA/CD or CSMA/CA to support Ethernet technology
Which switching method can be implemented using fast-forward switching or fragment-free switching?
cut-through switching
What are two methods for switching data between ports on a switch?
cut-through switching; store-and-forward switching
The physical layer of the receiving device passes bits up to which higher level layer?
data link
Which is a valid hexadecimal number?
f
What are two services performed by the data link layer of the OSI model?
it provides media access control and performs error detection; It accepts Layer 3 packets and encapsulates them into frames.
Which topology displays networking device layer IP addresses?
logical topology
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
Which of the following fiber-optic cable types can help data travel approximately 500 meters?
multimode
Which of the following fiber-optic cable types is used within a campus network?
multimode
What type of cable is used to connect a workstation serial port to a Cisco router console port?
rollover
Which of the following fiber-optic cable types can travel approximately 100 km?
single-mode
Which of the following fiber-optic cable types is used to connect long-distance telephony and cable TV applications?
single-mode
Which network device makes forwarding decisions based on the destination MAC address that is contained in the frame?
switch
Which characteristic describes crosstalk?
the distortion of the transmitted messages from signals carried in adjacent wires
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 is a possible cause of the signal distortion?
the microwave oven
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
Which procedure is used to reduce the effect of crosstalk in copper cables?
twisting opposing circuit wire pairs together
How many bits are in an IPv4 address?
32
What is the decimal equivalent of the hex number 0x3F?
63
What are the two sizes (minimum and expected maximum) of an Ethernet frame?
64 bytes; 1518 bytes
Which of the following are data link layer protocols?
802.11; Ethernet; PPP
Media Access Control (MAC)
Implements this sublayer (IEEE 802.3, 802.11, or 802.15) in hardware. It is responsible for data encapsulation and media access control. It provides data link layer addressing and it is integrated with various physical layer technologies.
Which two engineering organizations define open standards and protocols that apply to the data link layer?
Institute of Electrical and Electronics Engineers (IEEE); International Telecommunication Union (ITU)
What will a host on an Ethernet network do if it receives a frame with a unicast destination MAC address that does not match its own MAC address?
It will discard the frame.
Which data link sublayer controls the network interface through software drivers?
LLC
Which data link sublayer works with the upper layers to add application information for delivery of data to higher level protocols?
LLC
What is another name for the OSI data link layer?
Layer 2
The IEEE 802 LAN/MAN data link layer consists of which two sublayers?
Logical Link Control; Media Access Control
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.
Which of the following is the most common network media?
UTP
Which layer of the OSI model is responsible for specifying the encapsulation method used for specific types of media?
data link
Which lists the Layer 2 and Layer 3 address fields in the correct order?
destination NIC address, source NIC address, source IP address, destination IP address
Which IPv4 address format was created for ease of use by people and is expressed as 201.192.1.14?
dotted decimal
True or false. Wireless LANs operate in full-duplex allowing all devices to send or receive data at the same time so the number of users does not impact performance.
false
True or false. Wireless is not well suited for enterprise networks.
false
Which of the following fiber-optic cable types use light emitting diodes (LEDs) as a data light source transmitter?
multimode
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
Which two types of memory buffering techniques are used by switches?
port-based memory buffering; shared memory buffering
Which of the following fiber-optic cable types use lasers in a single stream as a data light source transmitter?
single-mode
What type of physical topology can be created by connecting all Ethernet cables to a central device?
star
Which type of UTP cable is used to connect a PC to a switch port?
straight-through
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
