Final answer:
CSMA/CD is no longer necessary in modern Ethernet networks due to the adoption of full-duplex communication which prevents data collisions.
Step-by-step explanation:
Although Carrier Sense Multiple Access with Collision Detection (CSMA/CD) is a legacy protocol mechanism in Ethernet, it is no longer necessary in modern networks. This is because today's Ethernet networks use full-duplex communication, allowing simultaneous transmission and reception of data. In full-duplex mode, there are separate channels for sending and receiving data, which eliminates the possibility of collisions that CSMA/CD was designed to detect and resolve.
In the past, Ethernet networks often operated in half-duplex mode, sharing a single channel for both sending and receiving data. This made collisions possible when two devices transmitted simultaneously. CSMA/CD would then be used to manage these collisions by instructing the devices to stop transmitting and to try again after a random period. However, the modern switch-based Ethernet networks are configured to operate in full-duplex mode, making CSMA/CD obsolete. Switches create a dedicated path between source and destination, which means that collisions are no longer a concern.