The link layer or data link layer divides packet into frames, then individual frame is sent bit-by-bit to the physical layer (physical medium, such as cable or radio wave). The link layer plays a critical role in LAN environments, it defines how data is framed and transmitted addressed, and controlled over various types of network media. Devices on the same LAN use link layer protocols to exchange data frames efficiently (hardware standards IEEE 802.3).
Data link protocol
Ethernet
Ethernet is one of the most widely used data link layer technologies. It uses MAC (Media Access Control) addresses, these are typically unique hardware addresses assigned to Network Interface Cards which are assigned by device manufacturer and often read only.
MAC address
When a device on a LAN needs to communicate with another device on the same network, it uses ARP to map the IP address of the target device to its corresponding MAC address. MAC addresses play a crucial role in the delivery of data frames to the correct destination. Ethernet frames contain source and destination MAC addresses, a frame type, and a payload(data). (more on Ethernet)
Wi-Fi (IEEE 802.11)
Wi-Fi is a wireless data link technology that enables devices to communicate over radio frequencies. It includes protocols for authentication, association, and data frame transmission in a wireless network.
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Computer_networksINFO1112IPLink_layerEthernetLANWANMAC_address