By AMULRAJ.A

Networking

CCNP Exam infoCCNPBSCI(Building scalable Cisco

Internetworks)642-811Switching Exam(Building Cisco Multilayer

Switched Network)642-821Remote Access Exam(Building Cisco Remote

Access Network642-831Support Exam(Cisco Internetworking

Troubleshooting

Elective640-822Internetworking Cisco Networking Devices Part1

NetworkingDef: A network is a group of two or more

computer systems linked together.A network is a connection Interface between

more than one device.To connect two or more computers together

with the ability to communicate with each other.

Networking began its infancy in the mid -1960’s.by the US Department of Defence (DoD).

The original intention of networking was being developed to withstand a nuclear war.

Telephone networks were to vulnerable and wouldterminate all conversations should a nuclear waroccur.

WE ARE DEALING WITH MACHINES INSTEAD OF PEOPLE IN TODAY’S WORLD. OUR PRIVACY IS AFFECTED AND ALMOST ALL OF OUR PERSONAL INFORMATION CAN BE FOUND IN THE “VIRTUAL WORLD” .

Berkeley developed a convenient program interfaceto the network and wrote many applications, utility,and management programs to make networking easier.

In it early infancy, the OSI protocols were crushed andthe TCP/IP protocols were already in widespread use.

The OSI Model had seven layers because at the time,IBM had a propriety seven -layer protocol calledSNA (Systems Network Architecture).

At the time, IBM dominated the computer companiesand every was scared to death that IBM would useits clout to force everyone to use SNA.

The OSI was to be produced like an IBM-reference model.

The OSI model became the world standard and wasnot controlled by one company, but by a neutralorganization, ISO (International Standards Association).

Use of NetworkingWired Network benefits:file sharingprinter / peripheral sharingInternet connection sharing multi-player gamesInternet telephone serviceWireless Network Benefits:Computer mobilityNo unsightly wires

Use of networking…File sharing: Network file sharing between

computers gives you more flexibity than using floppy drives or Zip drives , CD, DVD.

Not only can you share photos, music files, and documents, you can also use a home network to save copies of all of your important data on a different computer.

Use of networking…printer / peripheral sharing

Once a home network is in place, it's easy to then set up all of the computers to share a single printer. No longer will you need to bounce from one system or another just to print out an email message. Other computer peripherals can be shared similarly such as network scanners, Web cams, and CD burners.

Use of networking…Internet connection sharing:

Using a home network, multiple family members can access the Internet simultaneously without having to pay an ISP for multiple accounts. You will notice the Internet connection slows down when several people share it, but broadband Internet can handle the extra load with little trouble. Sharing dial-up Internet connections works, too. Painfully slow sometimes, you will still appreciate having shared dial-up on those occasions you really need it.

Use of networking…multi-player games

Many popular home computer games support LAN mode where friends and family can play together, if they have their computers networked.

Use of networking…Internet telephone service

So-called Voice over IP (VoIP) services allow you to make and receive phone calls through your home network across the Internet, saving you money.

Use of networking…Although you can realize these same

benefits with a wired home network, you should carefully consider building a wireless home network instead, for the following reasons:

Computer mobilityNo unsightly wires

Use of networking…Computer mobility:

Notebook computers and other portable devices are much affordable than they were a few years ago. With a mobile computer and wireless home network, you aren't chained to a network cord and can work on the sofa, on your balcony, or wherever in the house is most convenient at the moment.

Use of networking…No unsightly wires:

Businesses can afford to lay cable under their floors or inside walls. But most of us don't have the time or inclination to fuss with this in our home. Unless you own one of the few newer homes pre-wired with network cable, you'll save substantial time and energy avoiding the cabling mess and going wireless

Classification of NetworkPeer to Peer NetworkClient Server Network

Classification of NetworkingA model of communication where every node

in the network acts alike.

As opposed to the Client-Server model, where one node provides services and other nodes use the services.

Peer to Peer Networking

Uses of P2P NetworkingFile sharing• Instant messaging• Voice communication• Collaboration• Backup• Distributed computing

Advantages of NetworkingIt is easy to install. Configuration of computers is easy. Users can control their shared resources. The cost and operation of this network is less. It is ideal for small businesses having ten or

fewer computers. It needs an operating system and a few cables

to get connected. A full time network administrator is not

required

Disadvantage of networkingA computer can be accessed anytime. Network security has to be applied to each

computer separately. Backup has to be performed on each computer

separately. No centralized server is available to manage and

control the access of data. Users have to use separate passwords on each

computer in the network

Client server Networking

Clent Server NetworkingCentralized - Resources and data security are controlled through

the server.Scalability - Any or all elements can be replaced individually as

needs increaseFlexibility - New technology can be easily integrated into system. Backup � as all data is stored centrally it is easy to backup

Disadvantege of C-S NetworkingCan have a single point of failure.Server can get overloaded. Because beckup

server needed for files and data.Generally more expensive and difficult to set

up initially.More cost to maintain the system

Types of NetworkingLANMANWANPAN

TYPES OF NETWORKS

LAN – LOCAL AREA NETWORK IS A SMALL GEOGRAPHICAL AREA SUCH AS OUR SCHOOL BOARD.

MAN – METROPOLITAN AREA NETWORK IS A NETWORK OVER A LARGER GEOGRAPHICAL AREA SUCH AS THE REGIONAL(softlogic) GOVERNMENT.

WAN – WIDE AREA NETWORK IS A NETWORK USED OVER AN EXTREMELY LARGE GEOGRAPHICAL AREA SUCH AS THE CENTRALIZED(Google) GOVERNMENT.

A personal area network (PAN) is a computer network used for communication among computer devices, including telephones and personal digital assistants

Topologies Of NetworkingWhat is Topology?“The way in which the connections are made among all

the computers is called the topology of the network”.

Network topology specifically refers to the physical layout of the network, specially the location of the computers and how the cable is run between them.

BUS topology Star Ring mesh

Bus Topology…The bus topology is the simplest and most

common.

It is often used when a network installation is small, simple, or temporary.

It is a Passive topology. This means that computers on the bus only listen for data being sent, they are not responsible for moving the data from one computer to the next.

Bus topology…In an active topology network, the computers

regenerate signals and are responsible for moving the data through the network.

On a bus network, all the computer are connected to a single cable.

When one computer sends a signal using the cable, all the computers on the network receive the information, but only one (Addressee) accepts it. The rest disregard the message.

Bus topology…

Computer

Computer

Computer Computer

Computer Computer

Advantage of Bus The bus is simple, reliable in very small

network, and easy to use.

The bus requires the least amount of cable to connect the computers together and is therefore less expensive than other cabling arrangements.

Failure of one node does not affect the rest of network.

Disadvantages of BusHeavy network traffic can slow a bus

considerably.

A break in the cable or lake of proper termination can bring the network down.

It is difficult to troubleshoot a bus.

Suitability of busThe network is small

The least expensive solution is required

The network is not expected to grow much

Star TopologyIn a star topology, each device has a dedicated point

to point link only to central controller, usually called a hub/server/host.

Each computer on a star network communicates with a central hub that resends the message appropriate computer(s)

The hub can be active or passive.

An active hub regenerate the electrical signal and sends it to all the computers connected to it.

Star topology…This type of hub is often called a multiport

repeater.

Active hub require electrical power to run.

A passive hub, such as wiring panels, merely acts as a connection point and does not amplify or regenerate the signal.

Passive hubs do not require electrical power to run.

Star topology

Advantages of Star TopologyIt is easy to modify and add new computers to a star

network

During adding/deleting a node network can function normally.

When the capacity of the central hub is exceeded, it can be replaced with one that has a larger number of ports to plug lines into.

Provide for centralised monitoring and management of the network.

Single computer failure do not necessarily bring down the whole star network.

Disadvantages of Star TopologyIf the central hub fails, the whole network fails

to operate.

It cost more to cable a star network.

Require dedicated server and NOS

AppropriatenessIt must be easy to add or remove client

computer.

It must be easy to troubleshoot.

The network is large.

The network is expected to grow in the future.

Ring topology

Ring topology… In a ring topology, each computer is connected directly to the

next computer in line, forming a circle of cable.

It uses token to pass the information from one computer to another.

Every computer is connected to the next compute in the ring, and each retransmit what it receives from the previous computer.

The message flow around the ring in one direction.

Ring is an active topology.

There is no termination because there is no end to the ring

Advantage of ring…All the computers have equal access to the

network.

Allows error checking, and acknowledgement.

Disadvantage of ring…Failure of one computer can affect the whole

network.

It is difficult to troubleshoot the ring network.

Adding or removing computers disturbs the network

AppropriatenessThe network must operate reasonably under a

heavy load

A higher-speed network is required.

The network will not be frequently reconfigured.

Mesh topology…

Mesh TopologyIn a mesh topology, every devices has a

dedicated point to point link to every other device.

A fully connected mesh network therefore has n(n-1)/2 physical channels to link n devices.

To accommodate that many links, every device on the network must have n-1 input/output ports.

Advantages of Mesh TopologyBecause of the dedicated link, no traffic between

computers.

Failure of one node computer not affect rest of the network.

Because of the dedicated link privacy and security are guaranteed

Point to point links make fault identification and fault isolation easy.

Disadvantages of Mesh TopologyDue to the amount of cabling and number of

input output ports, it is expensive.

Large space is require to run the cables.

What type of topology?

What type of topology?

What type of topology?

What type of topology?

Other Topologies are…