It can also perform basic routing functions between virtual lans. We will conclude with the basic configuration of a switch and this will lead us into the discussion on vlans. A protocol is a set of rules or standards that two entities must follow so as to allow each other to receive and interpret messages sent to them. Switches and bridges are used for layer 2 switching. When an ethernet frame arrives at a layer 2 device, the layer 2 device will inspect the destination mac address of the frame and look to its fdb table for information on where to send that specific ethernet frame. Of the seven layers of the osi reference model, this lecture focuses on the ethernet implementation of layer 2 and the ip implementation of layer 3. This is done by specifying a default gateway address that points to a router or layer 3 switch.
Application layer is responsible for identifying and establishing the availability of desired. Network layer dlc 1 dlc 2 dlc 3 transport layer figure 3. A network can be defined as a group of computers and other devices. The osi uses a 7 layer model and tcpip networks use a 4 layer model. Our expert instructors draw upon their experiences to help you understand key concepts and how to apply. Presentation application session transport network data link physical layer 7 layer 6 layer 5 layer 4 layer 3 layer 2 layer. Mar 03, 2015 understanding basic layer 2 switching concepts. It is important to remember the order of the layers in the osi model. This layer is implemented as a method of establishing and maintaining reliable links between different nodes or devices on a network using existing physical connections. Dlc or to the transport layer if the node is the destination. Layer 2, also known as the data link layer, is the second level in the seven layer osi reference model for network protocol design. S1 is a layer 2 switch, so it makes forwarding decisions based on the layer 2 header.
Layer2 is the network layer used to transfer data between. Internet2s networking for cloud is a combination of cloud exchange and cloud connect. Before we move into these new terms, however, lets look at some standard layer 2, 3, and 4 network ing concepts. Describe the function and operation of layer 2 switching. Layer 2 service provisioning for the prime fulfillment consists of the layer 2 virtual private network l2vpn service, evc service and the virtual private lan service vpls. This chapter provides an overview of prime fulfillment layer 2 vpn concepts. Vmware virtual networking concepts in addition, virtual networks enable functionality not possible with physical networks today. Layer 2 switching layer 3 switching layer 4 switching highspeed scalability low latency compared to routers 2 1 physical 7 6 5 4 application presentation session 3 data link transport network. Layer 2 design and configuration abstract this paper presents recommended topologies and configurations for the layer 2 portion of a network topology which includes lenovo switches with cnos. Lan layer 2 qoscos protocol for traffic prioritization205.
A network node, which is just a device that forwards packets toward a destination, can be a router, bridge, or switch. Networking levels and layers and protocols a protocol defines a set of rules that govern how computers talk to each other. Overview of layer 2 networking techlibrary juniper networks. The network basics of bridging, routing, and switching dummies. Layer 2 switching or data link layer switching is the process of using devices mac addresses to decide where to forward frames. Jan 14, 2014 this layer can also break apart larger messages into smaller chunks to be reassembled on the opposite end. Demystify this portion of networking, so people dont drown in the alphabet soup. When a system needs to know another systems mac address, it sends a broadcast message to all systems on the network. Typically, the network layer adds its own header e. Within the discussion of content networking, we will. Tcpip tutorial and technical overview december 2006 international technical support organization gg24337607.
The negative effects of layer 2 loops grow as the network complexity i. Chapter 15 networking concepts ii puc, mdrpuc, hassan 5 p a g e keerthi kumar h m network as information is passed from source to destination. Mx series router architecture techlibrary juniper networks. Download basic networking interview questions and answers pdf for freshers and experienced which explain all networking concepts and commands ppt multiple choice. Ip, ipv4 address classes and subnetting and ipv6 explained for beginners. Overview of layer 2 networking techlibrary juniper. A layer 2 frame that is looping will stop only when a switch interface is shut down. When humans talk on the phone, they make a call, talk for a while, and then hang up. Presentation application session transport network data link physical layer 7 layer 6 layer 5 layer 4 layer 3 layer 2 layer 1. In figure 3 2, the network manager has placed ports 71, 31, and 3 2 in an ipx vlan. An introduction to networking terminology, interfaces, and. The key components of the juniper networks mx series 5g universal routing platforms are.
In this chapter, we will explore switching concepts and the basic configuration of a switch. Network is defined as a set of devices connected to each other using a physical transmission medium. Layer 2 and layer 3 refer to different parts of it network communications regarding layer networking and the standard for the osi model. A blog to start the best understanding of network implementation and to the troubleshooting of layer 2 and layer 3 protocols. It includes discussion of connectivity to upstream routed environments and downstream servers. Panos is very flexible, allowing administrators to mix and match physical firewall interfaces amongst virtual wire, layer 2, layer 3, and tap mode configurations. The data exchanged, known as protocol data unit pdu, goes back and forth through the layers, each layer adds or removes.
The reason we are having a discussion about layer 2 or layer 3, is that your choice of either layer has advantages and disadvantage in terms of scaling and costs. Basic networking questions asked in interview pdf download. Based on the work of daniil baturin daniil at baturin dot org under license ccbysa. Describe the concepts and use cases for layer 2 data link layer, ethernet networking 7% describe ethernet networking describe the standards of how ethernet operates and how addressing is used to move data on the ethernet network switching fundamentals and creating a switched network 23%.
This document explains panos layer 2 and vlan concepts, showing examples of connecting a vlan with layer 2 interfaces to a layer 3 interface for connectivity off of the vlan network. On the internet, ip addresses are used to identify hosts at the network layer. Selected sections from 2 ethernet, particularly switched ethernet. When configuring the ethernet ports on your firewall, you can choose from virtual wire, layer 2, or layer 3 interface deployments. This guide is for vmware infrastructure users who want a clearer understanding of the basic design of the networking capabilities in vmware infrastructure and how that design affects deployment in the datacenter. Introduction photo and see lots of wires on a single pole, it generally means they were telephone wires and not used to carry electricity. They break up one large collision domain into multiple smaller ones in a typical lan, all hosts are connected to one central device. 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. 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. We will discuss the switchs operation, layer 2 and layer 3 switching as well as other concepts.
In a typical layer 2 network, all users can see all devices by default. Before we dive into ip addresses, lets take a quick look at understanding binary numbers. Layer 1 physical layer 4 transport layer 2 data link layer ssession layer 3 network layer 6 presentation protocol typesicmpudptcpip connectionoriented vs. Because tcpip networks are the most common the tcpip model is the most important one to understand. Layer 2 protocols basically control access to a shared medium copper, fiber, electro magnetic waves. Fundamentals of computer networking and internetworking. Layer 2, also known as the data link layer, is the second level in the sevenlayer osi reference model for network protocol design. In a typical lan, all hosts are connected to one central device. Layer 2 of the osi model provides the following functions.
The book is aimed at all audiences even those with absolutely no prior tech. The internet protocol ip is the primary protocol at this layer. Chapter 1 introduction to networking and the osi model. Your layer 2 data will only be as good as your network configuration. Layer 2 networking concepts 205588a 35 protocolbased vlans as an example of using a protocolbased vlan, a network manager can create a vlan for the ipx protocol and place ports c arrying substantial ipx traffic into this new vlan. Let us start by setting up a very simple network of 2 computers, a server and a client, to. Doing so creates a better understanding of the network data flow. Address resolution protocol, or arp, is a layer 2 protocol that enables the communications between layer 2 and layer 3 by maintaining a mapping of ip addresses to mac addresses and vice versa. Layer 2 switching layer 3 switching layer 4 switching highspeed scalability low latency compared to routers 2 1 physical 7 6 5 4 application presentation session 3 data. A frame with a layer 3 address on it is often referred to as a packet. How computers connected to a layer 2 switch communicate with each other, explained in detail stepbystep. Layer 2 and layer 3 refer to different parts of it network communications. Preface the goal of this book is to provide a basic understanding of the technical design and architecture of the internet.
They break up one large collision domain into multiple smaller ones. They operate on different layers of a networking protocol layered protocols make it easier to modify and implement the networking task. Ethernet and wifi are data link protocols that are responsible for framing data on the media cable or wireless. Here we go with the basic networking questions and answers.
Chapter 2 basic switching concepts and configuration 2. Tcpip concepts conceptually, the tcpip protocol stack consists of four layers, each layer consisting of one or more protocols. In addition, to allow you to integrate into a variety of network segments, you can configure different types of interfaces on different ports. The layers refer to how you configure an it network, and the standard for network communications called the osi model. Each entity at a layer n communicates only with entities at layer n1. In a properly designed network, lan switches are responsible for directing and controlling the data the flow at the access layer to networked resources. Understanding basic layer 2 switching part 1 youtube. 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. Protocol, layer that provides an abstraction for connecting multiple lans into, well, the.
Advanced layer 1 services provide a highly specialized and costeffective toolkit to build a custom, highcapacity network on the most advanced research collaboration platform in the world. Cisco prime fulfillment theory of operations guide 6. Switch concepts and configuration part i ccna blog. L2 and l3 networking protocol stack see ciscos internetworking basics for a discussion of the osi reference model and how it organizes the information flow from one host computer to another. Layer 2 is equivalent to the link layer the lowest layer in the tcpip network model. Notice that the bottom layer is identified as the first layer.
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