All of the above 12 what is a firewall in computer network. Ipv6 multicast addresses are defined for a group of networking devices. Introductiona network can be defined as a group of computers and other devices connected in some ways so as to be able to exchange data. Tcp segment structure reliable data transfer flow control connection management 3. Network security is not only concerned about the security of the computers at each end of the communication chain. Ethernet ethernet is a widely deployed lan technology. Contents at a glance introduction 1 selfassessment 21 chapter 1 networking fundamentals 29 chapter 2 network models 43 chapter 3 concepts in ip addressing 73 chapter 4 working with cisco equipment 7 chapter 5 securing your cisco devices 173 chapter 6 basic switch operations and configuration 193 chapter 7 basic routing 229 chapter 8. Data pack ets sent to a multicast address are sent to the entire group of networking devices such as a group of routers running the same routing protocol. This part of the book introduces networking concepts and explains both the osi. Chapter 2 communicating over the network 33 chapter 3 application layer functionality and protocols 63 chapter 4 osi transport layer 99 chapter 5 osi network layer 5 chapter 6 addressing the network.
Apr 06, 2014 layer 3 refers to the third layer of the open systems interconnection osi model, which is the network layer. An introduction to networking terminology, interfaces, and. In the seven layer osi model of computer networking, the network layer is layer 3. In a policybased vlan, ports are designated as always a member, never a member, or a potential member of the vlan. Layer 3 networks are built to run on on layer 2 networks. In this section, you will learn about the access, distribution, and core layers and their role in the hierarchical network model. Network models are organized into layers, with each layer representing a specific networking function. Layer 2 networking concepts 205588a 3 3 figure 3 1. Ipv4 171 chapter 7 osi data link layer 243 chapter 8 osi physical layer 279 chapter 9 ethernet 3 chapter 10 planning and cabling networks 367. Introduction a computer network is the infrastructure that allows two or more computers called hosts to communicate with each other. Layer 3 switches are compared to traditional multiprotocol routers.
The network achieves this by providing a set of rules for communication, called protocols, which should be observed by all participating hosts. Both can support the same routing protocols, inspect incoming packets and make dynamic routing decisions based on the source and destination addresses inside. Every effort has been made to make this book as complete and as accurate as possible, but no warranty or fitness. Preparing for handson activities 25 getting started with microsoft azure 25 1. The data exchanged, known as protocol data unit pdu, goes back and forth through the layers, each layer adds or removes. Best effort has been made to make this book as complete and. The layer 3 packet cant use layer 2 mac addresses, so the ip address scheme was created for layer 3. Multiple choice questions of computer networking 11 computer network is a. This technology guide examines the concepts and realities oflayer 3 switching and the requirements common to any modern internetwork are identified. These comparisons are based on the original seven layer protocol model as defined in iso 7498, rather than refinements in the internal organization of the network layer. Careers ccna security supports students who plan to start a career, build a career, or switch focus in an it networking career to security technologies. These functions are controlled by protocols, which are rules that govern endtoend communication between devices.
When humans talk on the phone, they make a call, talk for a while, and then hang up. Layer 3 switches technically have a lot in common with typical routers, and not just in physical appearance. Routing protocols and concepts, ccna exploration companion guide is the official supplemental textbook for the routing protocols and concepts course in the cisco networking academy ccna exploration curriculum version 4. The network basics of bridging, routing, and switching. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. The practice of implementing multiple layers of protection is known as defense in depth. Layer 3 the network layer layer 3, the network layer of the osi model, provides an endtoend logical addressing system so that a packet of data can be routed across several layer 2 networks ethernet,token ring, frame relay, etc. An introduction to computer networksis a free and open generalpurpose computer networking textbook, complete with diagrams and exercises. An ip address is just a set of four numbers between 1 and 254, separated by dots. The ethernet specification is the result of an extensive collaborative effort of the three corporations, and several years of work at xerox on an earlier prototype ethernet. Before becoming an instructor for ecpi, he spent almost 30. The book is more sufficiently comprehensive for an a single or introductory networking class for in an ee or cs program. An ethernet switch is classified as a bridge and therefore operates at the data link layer while routers operate at the network layer.
The internet layer is used to transport data from node to node in a network. Network interface layer d communication between a computer and network hardware. Here we go with the basic networking questions and answers. Each layer plays its part in moving data from one device to another across a net.
Computer networking 101 hh rev1 page 8 ethernet ethernet is a lower layer network protocol is commonly used with tcpip and over lans. Explain the concepts and characteristics of routing and switching. A router works with ip addresses at layer 3 of the model. Advanced networking concepts applied using linux on ibm. It can also perform basic routing functions between virtual lans. An introduction to computer networks open textbook library.
The layout pattern using which devices are interconnected is called as network topology. Although a different frame at least as far as mac addresses are concerned is sent hopbyhop through the network, the data content of the frame, called the layer 3 packet, remains intact from source host to destination host. Tcpip is responsible for you having an ipaddress and delivers the possibility to the computer to communicate with other systems using ipaddresses, a subnetmask, portnumbers and a. It is an encapsulating protocol similar to the way ethernet is an encapsulating protocol. Learn the basics of risk analysis, industrial networking, and network security define the concepts of defense in depth and zones and conduits learn how to apply key risk mitigation techniques such as antivirus, patch management. Electronic copies of this book in epub, pdf, and html are licensed under a. Tcpip tutorial and technical overview lydia parziale david t. It can build up unreliable or reliable connections depending on the type of protocol used. Ipsec, vpn, and firewall concepts this appendix introduces the concepts of internet security protocol ipsec, virtual private networks vpns, and firewalls, as they apply to monitoring with performance monitor. The lowest layer is the physical layer that defines the basic signalling on the medium. For a more intuitive representation of ipv4 addresses, the 32 bits can be divided into four 4octet 1 octet, or byte, 8 bits groupings separated by dots, which is called dotteddecimal notation.
A layer 3 switch is a highperformance device for network routing. The figure below shows the ethernet protocol stack in relation to the tcpip protocol stack. Principles, protocols and practice, release techniques allow to create pointtopoint links while radiobased techniques, depending on the directionality of the antennas, can be used to build networks containing devices spread over a small geographical area. This collection of computer networking mcq questions includes s of objective type multiple choice questions on basic network theory with network definition, network models, connectivity and network addressing, introduction to osi and tcpip network reference models, layers of tcpip and osi model with physical layer, data link layer, network layer, transport layer, session layer. Notice that the bottom layer is identified as the first layer. Networking basics is the first course of the updated ccna v5 curriculum offered by the cisco networking academy. Advanced networking concepts applied using linux on ibm system z lydia parziale ben louie eric marins tiago nunes dos santos srivatsan venkatesan understand the ibm zvm failover concepts build a practical network solution using linux on system z configure routers and switches for redundancy. The more people in your network, the better your chances of finding that perfect job. As mentioned before, the layer 3 header contains a source ip address field and a destination ip address field. It is a reference model that specifies standards for communications protocols and also the functionalities of each layer. In an ip layer 3 network, the ip portion of the datagram has to be read. Ip addresses are 32 bit long, hierarchical addressing scheme. S1 is a layer 2 switch, so it makes forwarding decisions based on the layer 2 header. Understanding layer 2, 3, and 4 protocols hile many of the concepts well known to traditional layer 2 and layer 3 networking still hold true in content switching applications, the area introduces new and more complex themes that need to be well understood for any successful implementation.
Metropolitan area network man 32 wide area network wan 32 2. Chapter 1 introduction to networking and the osi model. A blog to start the best understanding of network implementation and to the troubleshooting of layer 2 and layer 3 protocols. A network can be as small as distance between your mobile phone and its bluetooth headphone and as large as the internet itself, covering the whole geographical world. The ohio state university raj jain 8 layer 3 vlans q also known as virtual subnet q vlan membership implied by mac layer protocol type field and subnet field 123. Layer 3 switches the layer 3 switch functions at the network layer and performs the multiport, virtual lan, data pipelining functions of a standard layer 2 switch. The ethernet a local area network, data link layer and. Preface the goal of this book is to provide a basic understanding of the technical design and architecture of the internet. Bestselling authors and expert instructors keith barker and kevin wallace share preparation hints and testtaking tips, helping you identify areas of weakness and improve. Fundamentals of computer networking and internetworking. Layer 3 network layer overview next we move on to the network layer, layer 3 of the osi model which controls broadcast domains. The link layer corresponds to the osi data link layer and may include similar functions as the physical layer, as well as some protocols of the osis network layer.
The network layer layer 3 whereas layer 4 is concerned with transport of the packets within a communication channel, the network layer is concerned with the delivery of the packets. Tcpip tutorial and technical overview ibm redbooks. Britt chuck davis jason forrester wei liu carolyn matthews nicolas rosselot understand networking fundamentals of the tcpip protocol suite introduces advanced concepts and new technologies includes the latest tcpip protocols front cover. It covers the lan, internetworking and transport layers, focusing primarily on tcpip. The tcpip protocol suite has no specific mapping to layers 5 and 6 of the model. Example of portbased vlans policybased vlans a policybased vlan is a vlan in which ports are dynamically added to the vlan based on the traffic coming into the port. This is done by specifying a default gateway address that points to a router or layer 3 switch. This technology was invented by bob metcalfe and d. Telecommunications concepts after a few ideas have sunk in, we move on to a highspeed data networking strategy, with the use of frame relay. The tcp and udp transports map to layer 4 transport. Network security entails protecting the usability, reliability, integrity, and safety of network and data. Module 4 discuss how broadcast are performed, the devices that work at the network layer, then we explain in details what happens to the data that facilitates its transmission over the network.
The seven layers of the osi reference model osi sounds like the name of a topsecret government agency you hear about only in tom clancy novels. A simpler strategy might be to include the price of the book in the course. Wireless networking technology from principles to successful implementation steve rackley amsterdam boston heidelberg london new york oxford paris san diego. This book is designed to provied information about the current network communication protocols. This identification is an ipinternet protocoladdress. Explain devices, applications, protocols and services at their appropriate osi layers. In order to send and direct data across a network, computers need to be able to identify destinations and origins.
Introduction photo and see lots of wires on a single pole, it generally means they were telephone wires and not used to carry electricity. How useful is a layer 3 switch for network routing. The network layer provides the means of transferring variablelength network packets from a source to a destination host via one or more networks. Networking academy ccna, ccnp, network security, fundamentals of wireless lan, and ip telephony curricula. Data communication and computer network 8 let us go through various lan technologies in brief. This requires stripping off the datalink layer frame information. Ip is a standard that defines the manner in which the network layers of two hosts interact. It is when used in concert with other works, in particular, that this book s being free is of marked advantage. It is demonstrated that layer 3 switching is simply a reinvention of the router using new switchbased technologies. If multiple networks are connected to a switch, you need to specify how the switch forwards the internetwork frames, because the path must be determined at layer three. This document contains the specification of the ethernet, a local area network developed jointly by digital equipment corporation, intel corporation, and xerox corporation.
Advanced networking concepts applied using linux on ibm system z. Os you are using and is running on osi layer 3 and 4 the network and transport layer. This course describes the architecture, components, and operation of routers, and explains the principles of routing and. Network which uses shared media has high probability of. Introduction 3 network layer supervises hosttohost packet delivery hosts could be separated by several physical networks datalink layer provides nodetonode delivery, transport layer provides processtoprocess delivery major basic network layer duties addressing. Introducing basic network concepts 3 basetech networking concepts team 2230894 blind folio 3 figure 1. For the remainder of this text, the term networkwill. Protocols on one layer will interact with protocols on the layer above and below it, forming a protocol suite or stack. Within the service layering semantics of the osi network architecture, the network layer responds to service requests from the transport layer and issues service requests to. When we talk about layer 2 and layer 3 networking, it is these layers that were referring to, and logically the further up the osi model we move, the greater intelligence we can use in networking decisions. Describe the functionality of lan, man, and wan networks. This level of networking utilizes ports to address different services.
Reviewed by john hoag, associate professor, ohio university on 2118. Presentation application session transport network data link physical layer 7 layer 6 layer 5 layer 4 layer 3 layer 2 layer. After frame relay, we discuss the use of atm for its merits and benefits. Network is defined as a set of devices connected to each other using a physical transmission medium. A layer 3 switch is a specialized hardware device used in network routing. The book is aimed at all audiences even those with absolutely no prior tech. Each entity at a layer n communicates only with entities at layer n1. The most significant protocol at layer 3 also called the network layer is the internet protocol, or ip. Data communication and computer network 3 generally, networks are distinguished based on their geographical span.
Within the discussion of content networking, we will. Protocol, layer that provides an abstraction for connecting multiple lans into, well, the internet. Ip is the standard for routing packets across interconnected networkshence, the name internet. What it really stands for in the networking world is open systems interconnection, as in the open systems interconnection reference model, affectionately known as the osi model. When we talk about layer 2 and layer 3 networking, it is these layers that. The transport layer is responsible for communication between processes. Basics of tcpip, switching, routing and firewalling. The network layer is responsible for packet forwarding including routing through intermediate routers. The book is released under a creative commons licence. Layer 3 layer 4 layer 5 d descriptive model formed after tcpip protocols were devised. Physical and data link layers through the use of bridges and repeaters.
Warning and disclaimer this book is designed to provide information about the cisco network fundamentals ccna exploration course. If managing the switch from a remote network, a default gateway must also be configured the ip information address, subnet mask, gateway is to be assigned to a switch svi switch virtual interface although these ip settings allow remote management and remote access to the switch, they do not allow the switch to route layer 3 packets. Transmission control protocol tcp user datagram protocol udp primary responsibilities of transport layer protocols. The text is extracted directly, wordforword, from the online course so students can highlight important points and take notes in the your chapter.
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