QUESTIONS AND CORRECT ANSWERS
What is Ethernet? - CORRECT ANSWER Collection of protocols for Link layer of
TCP/IP model
What are the data rates of Ethernet? - CORRECT ANSWER Originally up to 10 Mbps,
now up to 400 Gbps
What was the original topology of Ethernet? - CORRECT ANSWER Bus topology
with potential collisions
What type of transmission was added to Ethernet? - CORRECT ANSWER Full-duplex
transmission
Where is Ethernet used now? - CORRECT ANSWER Metropolitan and wide area
networks
What types of cabling does Ethernet use? - CORRECT ANSWER Twisted pair and
optical fiber
What does 100BASE indicate? - CORRECT ANSWER 100 Mbps with base
modulation over twisted pair cable
What is the optical fiber variant of Ethernet? - CORRECT ANSWER 100BASE-SX
What does full duplex indicate? - CORRECT ANSWER Simultaneous bidirectional
transmission is possible
What does half duplex indicate? - CORRECT ANSWER Only one node can transmit at
a time
What is auto-negotiation in Ethernet? - CORRECT ANSWER when peer nodes
describe their capabilities to each other and agree on the way they will communicate.
What happens if auto-negotiation is disabled? - CORRECT ANSWER it will not issue
or respond to messages associated with this function, and will not modify the way it operates
What happens if auto-negotiation is limited? - CORRECT ANSWER Operates
according to set limitations, no modification
, What is the bus topology in Ethernet? - CORRECT ANSWER Devices compete to
avoid disrupting transmission, basically fighting to use a one way street.
What is CSMA-CD in Ethernet? - CORRECT ANSWER Carrier sense multiple access
with collision detection
What is carrier sense in Ethernet? - CORRECT ANSWER Hosts sense medium before
transmission, and will not send a transmission if another host is sending one.
What is collision detection in Ethernet? - CORRECT ANSWER Detection and
handling of simultaneous transmissions
What happens when collisions occur in Ethernet? - CORRECT
ANSWER Transmission stops and hosts wait random period of time
What causes CSMA-CD to lose efficiency? - CORRECT ANSWER Time spent by
hosts sensing medium, hosts having to stop sending messages, only one host being able to use
medium at a time.
What is a point-to-point connection? - CORRECT ANSWER A connection with two
separate physical links, one for transmission in each direction, making it full duplex and
avoiding collisions.
What is the purpose of a hub? - CORRECT ANSWER To replicate frames at the
physical layer, requiring CSMA-CD to avoid collisions.
What is a switch? - CORRECT ANSWER A device that only forwards frames when it
is safe to do so, creating independent collision domains.
What is the format of a MAC address? - CORRECT ANSWER 48 bits expressed as 12
hexadecimal digits, with the first 6 digits representing the OUI and the last 6 digits uniquely
assigned by the vendor.
What is an unicast MAC address? - CORRECT ANSWER An address assigned to a
physical interface, used when a frame is meant for a specific host.
What happens when a frame with a unicast address is received by multiple nodes? -
CORRECT ANSWER Only the node with a matching assigned MAC address will
accept and process the frame.