Which data link layer protocol is commonly usedin local area networks (LANs)?a) ARPb) TCPc) DNSd) CSMA/CD

Identifying the Correct Data Link Layer Protocol

To determine which data link layer protocol is commonly used in local area networks (LANs), let's analyze the options provided:

1. ARP (Address Resolution Protocol): This protocol operates at the network layer (Layer 3) and is used for mapping an IP address to a physical machine address (MAC address).

2. TCP (Transmission Control Protocol): TCP is a transport layer protocol (Layer 4) and is responsible for reliable data transmission over a network.

3. DNS (Domain Name System): DNS is an application layer protocol that translates human-readable domain names into IP addresses. It does not function at the data link layer.

4. CSMA/CD (Carrier Sense Multiple Access with Collision Detection): CSMA/CD is a network protocol for local area networks that uses a method to control access to the network. Specifically, it is used in Ethernet networks, which are a common type of LAN.

Conclusion

The correct answer to the question of which data link layer protocol is commonly used in local area networks (LANs) is d) CSMA/CD. This protocol is integral to managing how devices on a LAN communicate and ensures efficient use of the network medium.