ccna 200-301 official cert guide library ebook

ccna 200-301 official cert guide library ebook.This chapter focuses on several common approaches to network classification and the two main network reference models. Introducing network communication from human communication, the two main network models ISO/OSI and TCP/IP reference models are introduced.The reader is expected to understand the concept of layering, understand the functions and services of the relevant layers, master IP address classification and subnetting, and understand common network transmission media and network devices. In this chapter, the reader will gain experience using networking tools and software, such as Sniffer, which will not only help the reader understand the layering of protocols and the flow of data through the network, but also help the reader troubleshoot the network in engineering.Classification of Networks"Simply put, a network is the connection of two or more computers in a certain area in a certain way for users to share resources such as files, programs, and data. The following is a brief description of several common types of networks and how they are classified.2.1.1 By Coverage*.. LocalAreaNetwork (LAN):LAN is generally within the range of tens to thousands of meters, and a LAN can accommodate several to thousands of computers. LANs generally have the following characteristics: LANs are distributed in a relatively small geographical area. Because transmission media and transmission devices with different transmission capabilities can be used, the transmission distance and transmission speed of LANs also vary; LANs are often used for a certain group of people. For example, a company, a unit, a building, a ...school, etc. , .. MetropolisAreaNetwork (MAN): MAN is a regional network limited in size to a city. The speed of MAN is faster than WAN, which is in line with the trend of broadband, so it is growing rapidly. Compared with LAN, MAN has the feature of wide geographical distribution, generally speaking, the coverage area of MAN is between 10.100km.. Wide Area Network (WAN): WAN is a network that connects local area networks distributed in different places, and is an "inter-network" (network between networks). o WAN has a very large range, and can cross national boundaries, continental boundaries, and even global scope.LANs form the basis for the other two types of networks, and metropolitan area networks are generally joined by WANs. The typical representative of WAN is the Internet. o There are two other more popular network concepts: StorageAreaNetwork (SAN) and VirtualPrivateNetwork (VPN). o SANs are dedicated high-performance networks that are used to transfer data between servers and storage resources. Since the SAN is a separate private network, any transmission conflicts between clients and servers can be avoided. VPN is a private network that transmits data over a public network on a private networkWith VPNs, a remote user or branch office can establish a secure tunnel with headquarters for the transmission of private data. This book has a special section on VPN concepts and configuration.2.1.2 Classification by Topology*