cisco ccna or comptia network+

cisco ccna or comptia network+.L2 - Data Link Layer L2 - Data Link Layer L2 - Data Link Layer L2 - Data Link Layer" j L2 - Data Link Layer!<-L1-Physical Layer L1-Physical Layer L1-Physical Layer L1-Physical LayerFigure 1-8 Interaction between the layers of the OSI modelHost Server BThroughout the rest of the book, the names of the layers of the OSI model and the TCP/IP model will be used interchangeably.1.3 Layer 2 Basics and Technologies This section will cover link layer (or layer 2) basics. While the CCNACyber OpsSECFND exam does not require candidates to master specific implementations and configurations, it does require candidates to understand various link layer technologies, such as the principles of HUBs, bridges, and switches and how they operate. Candidates are also required to master the various protocols that implement link layer communications. Readers interested in Layer 2 technologies and protocol-related details should refer to the CCNA Routing and Switching books to gain a more comprehensive knowledge of the subject. Local Area Network (LAN) and Wide Area Network (WAN) are two familiar technical terms used to describe Layer 2 communication networks. As their names imply, LANs cover a number of devices, protocols, and technologies that interact with each other in close proximity, while WANs involve devices, protocols, and technologies that are used to carry information over long distances. Two common types of LANs are described below: wired LANs (with a focus on LANs based on Ethernet technology) and wireless LANs.1.3.1 Ethernet LAN Fundamentals and TechnologiesEthernet is a protocol that provides data transmission and services for the physical and data link layers, as defined in the IEEE802.3 standard set. The Ethernet standard is an offshoot of the broader IEEE 802 standard that defines LAN communications.14 Chapter 1 Network Protocols and Network Device Basics