CCNA Intro Class

7/28/2019 CCNA Intro Class

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Introduction class

CCNA-Cisco Certified Network

Associate



What is a computer

An electronic device for the storage and processing of information

A device or system that is capable of carrying out asequence of operations in defined manner

Any device capable of processing information toproduce a desired result. No matter how large or smallthey are, computers typically perform their work inthree well-defined steps: (1) accepting input, (2)

processing the input according to predefined rules(programs), and (3) producing output



Components of a computer

Input device

Processing Unit

Memory Unit

Storage unit

Output device



Boot up process

The first step of POST (Power On Self Test) is thetesting of the Power Supply to ensure that it isturned on and that it releases its reset signal

CPU must exit the reset status mode and

thereafter be able to execute instructions BIOS must be readable BIOS checksum must be valid, meaning that it

must be readable

CMOS ( Complementary metal oxidesemiconductor )be accessible for reading



Boot up process

CMOS checksum must be valid, meaning that it mustbe readable

CPU must be able to read all forms of memory such asthe memory controller, memory bus, and memorymodule

The first 64KB of memory must be operational andhave the capability to be read and written to and from,and capable of containing the POST code

I/O bus / controller must be accessible

I/O bus must be able to write / read from the video

subsystem and be able to read all video RAM



Trouble shooting using Beep codes

1 Beep: DRAM refresh failure

2 Beeps: Parity circuit failure

3 Beeps: Base 64K RAM failure

4 Beeps: System timer failure

5 Beeps: Processor failure 6 Beeps: Keyboard controller

7 Beeps: Virtual mode exception error

8 Beeps: Display memory read/write failure

9 Beeps: ROM BIOS checksum failure 10 Beeps: CMOS shutdown register read/write error

11 Beeps: Cache memory error

Continuous Beeping: Memory or video problem



Topology in Network Design

The way in which the devices are connected in thenetwork.

Network topologies are categorized into the following

basic types: bus

star

tree

mesh

ring

FDDI



Bus Topology

Bus networks use a commonbackbone to connect all devices.

A single cable, the backbonefunctions as a sharedcommunication medium, thatdevices attach or tap into with aninterface connector .

A device wanting to communicate with another device on thenetwork sends a broadcast messageonto the wire that all other devicessee, but only the intended recipient

actually accepts and processes themessage.



Mesh Topology

Mesh topologies involve the concept of routes . Unlikeeach of the previous topologies, messages sent on amesh network can take any of several possible pathsfrom source to destination. # ( All the routes are openfor all the devices to communicate because each deviceis connected to all the devices in the network. But asthis N/W uses more cabling it is costly).

(Recall that in a ring, although two cable paths exist,messages can only travel in one direction.)

Some WANs, like the Internet, employ mesh routing.



Basic Networking Concepts

Network occurs any time you connect two ormore computers together so that they can shareresources

A network is any collection of independentcomputers or devices that communicate withone another over a shared network medium.



Area Networks

Local Area Network (LAN)

Wide Area Network (WAN)

Metropolitan Area Network (MAN)

Storage Area Network (SAN)

System Area Network (SAN)

Server Area Network (SAN)

Small Area Network (SAN)

Personal Area Network (PAN)

Desk Area Network (DAN)

Controller Area Network (CAN)

Cluster Area Network (CAN)



MAN

A MAN is a relatively new class of network, it serves a role similar to an ISP,but for corporate users with large LANs.

There are three important features which discriminate MANs from LANs or WANs: The network size falls intermediate between LAN and WAN. A MAN typically

covers an area of between 5 and 50 km diameter. Many MAN cover an area the

size of a city, although in some cases MAN may be as small as a group of buildings or as large as the North of Scotland.

A MAN is not generally owned by a single organization. The MAN, itscommunications links and equipment are generally owned by either a consortiumof users or by a single network provider who sells the service to the users. Thislevel of service provided to each user must therefore be negotiated with the MANoperator, and some performance guarantees are normally specified. #(eg: city

cable operator) A MAN often acts as a high speed network to allow sharing of regional resources.

It is also frequently used to provide a shared connection to other networks using alink to a WAN



Internet

The Internet is a system of linked networks that are worldwide inscope and facilitate data communication services such as remotelogin, file transfer, electronic mail, the World Wide Web andnewsgroups.

Internet has become a communications highway for millions of users.

The Internet was initially restricted to military and academicinstitutions, but now it is a full-fledged conduit for any and allforms of information and commerce.

Internet websites now provide personal, educational, politicaland economic resources to every corner of the planet.



Networking Devices

Hubs

Switches

Bridges

Routers

Gateways

CSUs/DSUs

Modems

Network Interface cards

ISDN Terminal Adapters

Wireless Access Point

Firewalls



Hubs

Hubs are simple network devices, and theirsimplicity is reflected in their low cost. Smallhubs with four or five ports (often referred to as workgroup hubs) with the requisite cables, they provide everything needed to create a small

network. Hubs with more ports are available for networks

that require greater capacity.

Computers connect to a hub via a length of twisted-pair cabling. In addition to ports for

connecting computers, (even an inexpensivehub generally has a port designated as an uplink port that enables the hub to be connected toanother hub to create larger networks.



Thank you

F.Hina B.E.

IT Architect

D ll D S

CCNA Intro Class

Documents

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