Cn Notes.docx

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Practical-1 Aim: Installation of Packet Tracer. Packet Tracer is a cross-platform visual simulation tool designed by Cisco Systems that allows users to create network topologies and imitate modern computer networks. The software allows users to simulate the configuration of Cisco routers and switches using a simulated command line interface. Packet Tracer makes use of a drag and drop user interface, allowing users to add and remove simulated network devices as they see fit. The software is mainly focused towards Certified Cisco Network Associate Academy students as an educational tool for helping them learn fundamental CCNA concepts. Previously students enrolled in a CCNA Academy program could freely download and use the tool free of charge for educational use.

Features Cisco Packet Tracer includes the following features: • Makes teaching easier by providing a free, multiuser environment for instructors to easily teach complex technical concepts . • Makes learning easier by providing a realistic network simulation and visualization environment. • Provides authoring of learning activities, tasks, labs, and complex assessments. • Supports lectures, group and individual labs, homework, assessments, case studies, games, and competitions.

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• Supplements real equipment and enables extended learning opportunities beyond physical classroom limitations. • Simulates continuous real-time updates of underlying network logic and activities. • Empowers students to explore concepts, conduct experiments, and test their understanding. • Promotes social learning through a network-capable (peer-to-peer) application with opportunities for multiuser competition, remote instructor-student interactions, social networking, and gaming.

Advantages: 1) It is easy to use and can be used on the any place you want. 2) One of the best advantage of it is the Sim mode which otherwise don’t available in the real gear thing. 3) It enables it’s users to simulate the configuration relating to the Cisco routers

Disadvantage: 1) It may cause the loops by affecting the STP. 2) It doesn’t support the ether channel regarding the access layer switches. 3) With regard to the Frame relay it is low in command.

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STEPS TO INSTALL PACKET TRACER: 1. The below screen appears. Select “I accept the agreement” and click on “Next“.

Fig:1.1 2. Setup will show the folder in which the program’s shortcuts will be created. If you want to change the folder, you can change it. Click on “Next“.

fig:1.2

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3. Then the program will ask whether to create a Desktop icon and create a Quick Launch icon. Make your own choice and click on “Next“.

fig:1.3 4. Then the summary of the settings we selected is displayed. Click on “Install“.

fig:1.4 5. The installation starts as shown below.

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fig:1.5 6. In seconds, installation gets completed and the below screen is shown. Click on “Finish“.

Fig:1.6 7. Then the below popup appearsasking you to close or restart your computer. Click on “OK“.

Fig:1.7 Chandigarh Engineering College

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8. As we selected Launch option, Packet tracer is automatically launched. It should look like below.

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Practical -2 Aim: To Install Wireshark INTRODUCTION: Wireshark is a free and open source packet analyzer. It is used for network troubleshooting, analysis, software and communications protocol development, and education. Originally named Ethereal, the project was renamed Wireshark in May 2006 due to trademark issues.[4] Wireshark is cross-platform, using the Qt widget toolkit in current releases to implement its user interface, and using pcapto capture packets; it runs on Linux, macOS, BSD, Solaris, some other Unix-like operating systems, and Microsoft Windows. There is also a terminal-based (nonGUI) version called TShark. Wireshark, and the other programs distributed with it such as TShark, are free software, released under the terms of the GNU General Public License.

INSTALLATION STEP: 1. Download Wireshark 2. Run Wireshark Click on NEXT to continue

3. Click “I Agree” to move to next step of installation.

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4. Select components and move to next step.

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5. Select the option as your preferences and click next

6. Select Directory

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7. Wait for Installation to be finished and click Next

8. Click to reboot your system

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9. Click on Wireshark application to launch it

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Practical - 3 Aim: Study of various networking devices. 1. Hubs A hub serves as a central point to which all of the hosts in a network connect to. It is an OSI layer 1 device. It receives a signal from one port and sends it out to all other ports. Sometimes it is called a multiport repeater

Today, these devices are considered obsolete and switches are commonly used instead. Hubs have numerous disadvantages. 1. They are not aware of the traffic that passes through them. 2. They create only one large collision domain. 3. A hub typically operates in half duplex. There is also a security issue with hubs since the traffic is forwarded to all ports (except the source port), which makes it possible to capture all traffic on a network with a network sniffer!

2. Switches Like hubs, a switch is used to connect multiple hosts together, but it has many advantages over a hub. Switch is an OSI Layer 2 device, which means that it can inspect received traffic and make forwarding decisions. Each port on a switch is a separate collision domain and can run in a full duplex mode. Chandigarh Engineering College

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Advantages of switches Increase available network bandwidth Reduced workload, computers only receive packets intended for them specifically Increase network performance Smaller collision domains

Disadvantages of switches More expensive than hubs and bridges Difficult to trace network connectivity problems through a switch Does not filter broadcast traffic

3. Routers A router is a device that routes packets from one network to another. A router is most commonly an OSI Layer 3 device. Routers divide broadcast domains and have traffic filtering capabilities.

How routers work

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A router uses IP addresses to figure out where to send packets. If two hosts from different networks want to communicate, they will need a router between them to route packets. Host A and host B are on different networks. If host A wants to communicate with host B, it will have to send a packet to the router. The router receives the packet and checks the destination IP address. If the destination IP address is in the routing table, the router will forward the packet out the interface associated with that network.

Advantages of routers Can connect networks of different architecture Token Ring to Ethernet Choose best path through or to a network Create smaller collision domains Create smaller broadcast domains

Disadvantages Of Routers Only work with routable protocols More expensive than hubs, bridges, and switches Routing table updates consume bandwidth Increase latency due to a greater degree of packet filtering and/or analyzing

4. Network Interface Card A network interface card is a computer hardware component designed to allow computers to communicate over a computer network. It is both an OSI layer 1 (physical layer) and layer 2 (data link layer) device, as it provides physical access to a networking medium and provides a low-level addressing system through the use of MAC addresses. It allows users to connect to each other either by using cables or wirelessly. Most motherboards today come equipped with a network interface card in the form of a controller, with the hardware built into the board itself, eliminating the need for a standalone card.

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5. Bridge Bridges can be identified by the fact that they operate at the data link layer of the OSI model. Bridges have intelligence and can "bridge" two of their ports together at very high speed. They use a database of MAC addresses to determine where computers are located and very efficiently send frames only where they need to go. The database is created dynamically as computers communicate on the network. A bridge simply watches the incoming frame and memorizes the MAC address and port a frame arrives on. It uses this information to locate a computer if a packet comes in that must be forwarded to it. If a frame arrives at the bridge and the bridge does not know where to send it, the bridge will flood the frame just like a hub does. Bridging is often inaccurately called switching. Advantages of using a bridge Extend physical network Reduce network traffic with minor segmentation Creates separate collision domains Reduce collisions Connect different architecture Disadvantages of using bridges Slower that repeaters due to filtering Do not filter broadcasts More expensive than repeaters

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6.GATEWAY In computer networking and telecommunications, a gateway is a component that is part of two networks, which use different protocols. The gateway will translate one protocol into the other. A router is a special case of a gateway. Gateways, also called protocol converters, can operate at any network layer. The activities of a gateway are more complex than that of the router or switch as it communicates using more than one protocol. Both the computers of internet users and the computers that serve pages to users are host nodes. The nodes that connect the networks in between are gateways. These are gateway nodes:  

the computers that control traffic between company networks the computers used by internet service providers (ISPs) to connect users to the internet

gateway must be implied on larger networks to interconnect them.

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Acoustic coupler modem

7. MODEM A modem (modulator–demodulator) is a network hardware device that modulatesone or more carrier wave signals to encode digital information for transmission and demodulates signals to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used with any means of transmitting analog signals, from light-emitting diodes to radio. A common type of modem is one that turns the digital data of a computer into modulated electrical signal for transmission over telephone lines and demodulated by another modem at the receiver side to recover the digital data.

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Practical – 4 Aim: To configure Ipv4 network Introduction: Internet Protocol version 4(IPv4) is the fourth version of the Internet Protocol(IP). It is one of the core protocols of standards-based internetworking methods in the Internet, and was the first version deployed for production in the ARPANET in 1983. It still routes most Internet traffic today,despite the ongoing deployment of a successor protocol,IPv6. IPv4 is a connectionless protocol for use on packet-switched networks. It operates on a best effort delivery model, in that it does not guarantee delivery, nor does it assure proper sequencing or avoidance of duplicate delivery. These aspects, including data integrity, are addressed by an upper layer transport protocol, such as the Transmission Control Protocol (TCP). Internet Protocol version 6(IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv6 was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion. IPv6 is intended to replace IPv4.IPv6 became a Draft Standard in December 1998, and became an Internet Standard on 14 July 2017

Steps for configuring Ipv4 : 1. Launch Packet Tracer and create a network.

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2. Configure PC1 with IP address 192.168.1.1 and PC2 with 192.168.1.2

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3. Use Ping command to check the connectivity

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Practical-5 Aim: To demonstrate wired communication between n terminals by router. STEPS: 1. Let us create wired topology on packet tracer. For this go to the wired devices and select link wired router, take some PCs and provide them with wired link module so that they can communicate through router wired. For that go to the PC physical mode as shown in the figures below.

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2. Now connect personal computer with wires to router.

3. Set IP address of both the personal computer.

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4. Apply IP address and put status on by interfacing in command line interfacing by configuring the router and set status of fast ethernet 1 / 0 or 0/0 .

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5. Now set the configuration of fast Ethernet 0/0 and give IP address of pc.

6. Now set the configuration of fast Ethernet 0/1 and give Ip address of pc.

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7. Now exchange msg between personal computer and check the status whether they are successful or not. Both pc are ready for communication.

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