Cisco CCNA mock exam questions sample test – Question 69

.Which of the following statements are TRUE regarding carrier sense multiple access collision detection (CSMA/CD)? (Choose three.)

A. Networks are segmented into multiple collision domains using switches for CSMA/CD networks.
B. Networks are segmented into multiple broadcast domains using switches for CSMA/CD networks.
C. CSMA/CD networks normally operate on half-duplex mode.
D. CSMA/CD networks normally operate on full-duplex mode.
E. Gigabit Ethernet uses CSMA/CD as the media access control method.
F. Gigabit Ethernet uses carrier sense multiple access with collision avoidance (CSMA/CA) as the media access control method.


Correct Answer: ACE

Explanation:
The following statements are true:
Networks are segmented into multiple collision domains using switches for CSMA/CD networks
CSMA/CD networks normally operate on half-duplex mode
Gigabit Ethernet uses CSMA/CD as its media access control method
CSMA/CD is a Local Area Network (LAN) access method used in Ethernet. In CSMA/CD, if a device or a node wants to send a packet in the network, it first determines if the network
is free. If the network is not free, then the node will wait before sending the packet into a network. If the network is free, then the node sends the packet; if another device sends a
packet simultaneously, their signals or packets collide. When the collision is detected, both packets wait for a random amount of time before retrying.
The option stating that networks are segmented into multiple broadcast domains using switches for CSMA/CD networks is incorrect because networks are segmented into multiple
broadcast domains using routers for CSMA/CD networks.
The option stating that CSMA/CD networks normally operate on full-duplex mode is incorrect; these networks normally operate on half-duplex mode.
The option stating that gigabit Ethernet uses CSMA/CA as the media access control method is incorrect because gigabit Ethernet uses CSMA/CD as the media access control
method.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Describe and verify switching concepts
References:
Cisco > Internetworking Technology Handbook > Introduction to LAN Protocols > LAN Media-Access Methods
Cisco > The Internet Protocol Journal – Volume 2, No. 3 > Gigabit Ethernet