When you design the core layer of your network you must make sure it will be reliable, meaning you have to use technologies able to carry large amounts of traffic and also provide a high level of redundancy, such as fddi, fastgigabit ethernet or atm. This is also the biggest difference lies between layer 2 switch and layer 3 switch. Get packets from the source to the destination hosts. The difference between layer 3 and layer 2 networks. There a minute difference between extending the network and internetworking. The internetworking technology ito cisco training on demand course is part of the. The data link layer, also sometimes just called the link layer, is where many wired and wireless local area networking lan technologies primarily. Chapter 2 application layer lecture 2 powerpoint file mp3 audio clip.
On the physical layer optical and electrical cabling technology are described as well as. Physical connections 7 2 internetworking technology overview logicallinkcontrolprotocol. A layer serves the layer above it and is served by the layer below it. Internetworking technological foundations and applications. Generally speaking, layer 2 is a broadcast media access control mac mac level network, while layer 3 is a segmented routing over internet protocol ip network. Internetworking technologies handbook has been one of cisco press bestselling and most popular books since the first edition was published in 1997. The primary difference between the two is that bridging occurs at layer 2 the link layer of the osi reference model, while routing occurs at layer 3 the network layer. Internetworking is enforced in layer three network layer of osiiso model. Network engineers, administrators, technicians, and support personnel use this book to understand and implement many different internetworking and cisco technologies. Here are some redirects to popular content migrated from docwiki. Preface the goal of this book is to provide a basic understanding of the technical design and architecture of the internet.
In order to design and configure these rapidly evolving networks, an understanding of multilayer switching technologies is essential. Routing operates at layer 3, where packets are sent to a specific nexthop ip address. Layer 3 refers to the third layer of the open systems interconnection osi model, which is the network layer. Sun network layer design the goal is to provide end to end transmission. What devices are used in each layer of the osi model. Bridges and switches are a data communications devices that operate principally at layer 2 of the osi reference model. Figure 3 28 provides a comparison between layer 3 and layer 2 vpns. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Internetworking is implemented in the network layer layer 3 of the model. Internetworking technologies handbook edition 3 by cisco.
In an ip layer 3 network, the ip portion of the datagram has to be read. Internetworking technology spring 2020 general information. This book selection from understanding the network. Page 2 of 4 objectives after completing this course, you should be able to. This requires stripping off the datalink layer frame information. The internet protocol suite, also called the tcpip model of the internet was not designed to conform to the osi model and does not refer to it in any of the normative specifications in requests for comment and internet standards. The osi model open system interconnection model defines a computer networking framework to implement protocols in seven layers. The growing dependence of enterprise networks on internet connectivity is forcing professional system and network administrators to turn to technologies that they may not fully understand for solutions. Internetworking multilayer switches global knowledge. This layer provides switching and routing technologies, creating logical paths, known as. Layer 3 networking is a little bit different, and overlays layer 2. Internetworking technologies handbook 158705001 3 chapter 1 internetworking basics open system interconnection reference model note a handy way to remember the seven layers is the sentence all people seem to need data processing. I agree that the technically correct and precise definition of vlan is that it a layer 2 entity. Internetworking basics computer and information science.
Understanding the difference between layer 2 and layer 3. I search in the command reference and i didnt find the connect command nor internetwork ip under the pw class. In detail, both versions, ipv4 as well as the successor ipv6 are covered in detail as well as icmp, ndp, and mobile ip. The data communications between different networks are not possible if there are no common rules for transmitting and receiving the. So its not really a case of counterposing layer 2 vs layer 3. The third stack layer works on the basis of ip addresses, not mac addresses. Osi 7 is conceptual, as the layers are abstractions that dont define the actual technology used. Background internetworking device comparison technology basics types of bridges types of switches. The main difference between layer 2 and layer 3 is the routing function. Next, layer 2 devices switches are introduced into the network.
Understanding the difference between layer 2 and layer 3 switches with regard to function and application, will open up new opportunities for technologists who want to diversify and grow their business. Layer 2 addresses are also called mac addresses, physical addresses, or burnedin addresses bia. If we are going to be precise about our terms then a vlan operates only at layer 2 and not at layer 3. Get internetworking technologies handbook, fourth edition now with oreilly online learning. Layer 3 networks are built to run on on layer 2 networks. When we are talking about layer 2 switches and layer 3 ethernet switch, we are actually referring to the layers of a generic protocol modelopen source interconnect osi model. Computer network term is used to describe two or more computers that are linked to each other. Layer 2 and layer 3 refer to different parts of it network. It is a commonly used in describing network communications. Layer 1 layer 2 layer 3 layer 4 layer 5 d descriptive model formed after tcpip protocols were devised. Internetworking technologies handbook, fourth edition, is a comprehensive reference that enables networking professionals to understand and implement contemporary internetworking technologies. Figure 12 illustrates the sevenlayer osi reference model.
Technical cisco content is now found at cisco community, and cisco devnet. It then introduces hosttohost communications using tcp ip. These are assigned to network cards or device interfaces when they are manufactured. Layer 3 switches are being used in a greater variety of commercial applications and even advanced residential projects. Introduction to internetworking 17 characteristics of the osi layers layer 7application layer layer 6presentation layer layer 5session layer layer 4transport layer layer 3 network layer layer 2 data link layer layer 1physical layer figure 1 2 illustrates the seven layer osi reference model. A router works with ip addresses at layer 3 of the model. A vlan was introduced in switching technology to reduce the size of the broadcast domain and operates at layer 2. Figure 3 28 provides a comparison between layer 3 and layer 2. Without layer 2, there would be no chance of creating wider networks via l3. Note a handy way to remember the seven layers is the sentence all people seem to need data. The difference between layer 3 and layer 2 networks aussie.
Many challenges must be faced, especially in the areas of connectivity, reliability, network management, and flexibility. Internetworking technology handbook tor hidden service. In this powerful fiveday course, extensive handson labs utilizing multivendor equipment will help you understand multilayer switching concepts, as well as how to design and configure a multilayer switch. Traditional switching operates at layer 2 of the osi model, where packets are sent to a specific switch port based on destination mac addresses. With layer 2 vpns, the information used to make forwarding decisions is based on layer 2 informationfor instance, via a mac address, via a vlan id, on dlci information, or on an input interface for lease line connectivity. The cisco docwiki platform was retired on january 25, 2019. Fourth edition, cisco systems inc, indianapolis 2004, isbn 158705 1192. Next, layer 3 devices routers are introduced into the network. This article discusses the difference between layer 2 and layer 3 switches and the appropriate use cases for each. This guide describes how to deploy layer 2 wan services, a remote site distribution layer switch, and wan qos. While generic routing encapsulation gre might seem to be a network layer protocol, if the encapsulation of the payload takes place only at the endpoint, gre becomes closer to a transport protocol that uses ip headers but contains complete layer 2 frames or layer 3 packets to deliver to the endpoint.
Data link layer layer 2 page 1 of 2 the secondlowest layer layer 2 in the osi reference model stack is the data link layer, often abbreviated dll though that abbreviation has other meanings as well in the computer world. Osi model is a conceptual model that defines a networking framework to implement protocols in layers, with control passed from one layer to the next. Lan switch bridging and switching basics background. Fundamentals of computer networking and internetworking.
Internetworking challenges implementing a functional internetwork is no simple task. Which layer 3 internetworking device should you use to accomplish this. Master the terms, concepts, technologies, and devices used. Merely exploitation of either a switch or a hub to attach 2 local area networks is an extension of lan whereas connecting them via the router is associate degree example of internetworking. Chapter 3 transport layer lecture 3 powerpoint file lecture 3 page 91 to 94. A layer 3 switch is a highperformance device for network routing. Layer 2 is responsible for encodeing decoding data packets into bits, it also handles errors in the physical layer, flow control and frame synchronization. Internetworking technologies handbook, fourth edition. For network engineers and architects, understanding the difference between a layer 3 and layer 2 network can greatly enhance the overall security and speed of your network infrastructure.
Internetworking started as a way to connect disparate types of computer networking technology. A protocol in the networking terms is a kind of negotiation and. Routing technologies conclude the treatment of the data link layer. Design a network to meet specific performance requirements explain the differences between a collision domain, broadcast domain, and a subnet describe how layer 3 to layer 2 address resolution methods work. A layer 2 switch works with mac addresses only and does not care about ip address or any items of higher layers. Because they operate at the network layer, they are fully aware of different network technologies, and can overcome such problems as interconnecting different network technologies. Describe how layer 3tolayer 2 address resolution methods work. The beginning letter of each word corresponds to a layer. L3 is responsible to get it from source to destination by deciding the path, and using l2 for each step along the path. Internetworking technologies handbook, 4th edition cisco. Next, there is the internet layer with the internet protocol ip that establishes a virtual uniform network out of the net of heterogeneous networks. Layer 3 provides switching and routing technologies, creating logical paths, known as virtual. Internetworking is implemented in layer 3 network layer of this model the most notable example of internetworking is the internet capitalized.
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