Introduction to Networks

Networking Concepts

IST-200

VWCC

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What is Networking?

Connecting computers

to form a

Local Area Network

( LAN )

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Device Sharing

Sharing of:•Hardware•Software•Information

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A Simple Network

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Local & Wide Area Networks

Early networks were custom built

Connecting a dozen computers

Only 1 or 2 peripherals

Early Ethernet30 userstotal span of 601 feet

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Local Area Network (LAN)

A single collection of machines & peripheralsGenerally less than 1000 computers“Spanned” generally less than 250 meters feetBasic building block for larger networks-Internetworks

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InterNetworks IntraNetworks

A network of networksA networked collection of LANsMore than one floor in a business (intranetwork)Multiple buildingsCampus environment

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Wide Area Networks (WAN)

Spans miles of distance

Two or more separate locations

Down the road or across the world

Microsoft, Federal Express

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The Internet

A WAN internetwork

Millions of machines worldwide

The World Wide Web (WWW)

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Networking Terminology

Client/Server relationship

Client requests shared resources

Server responds & shares resources

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Networking Terminology

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Client Server Networks

Concentrate CPU power & storage capacity

Windows NT Server / Server 2000

Peer to PeerClient/Server role interchangesWindows 95/98/2000/XP

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Simple Network Needs

Medium to carry data

Adapter (NIC)

Protocol

Client / Server Software

Local Network Medium (media)

Carries network messagesConnects machines together on

networkFour types:Metallic cable coaxial - datedTwisted pairFiber optic cable Wireless

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Network Interface Card

(NIC)

Physical link between machine & network

Connection between machine & medium

Also known as network adapter

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Network ProtocolsCommon set of communication rules

Identify ‘oneself” & others on network

Interpret signals

Begin & end network communication

Manage network information exchange

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Protocol Examples

TCP/IP for the Internet

IPX/SPX & NWLINK for Novell

NetBEUI for Microsoft

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Windows Client Setup

Control Panel

Networking

Protocols

Clients

Adapters

Network Software

Programs that access the network

Network Operating System (NOS)Windows NTNovell NetWare (IntranetWare)

Consist of client & server components

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Network LayersNetwork Applications ( NOS & client)Instruct network medium Using machines interface (NIC)Address & exchange informationTo other machines on LAN or WAN

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Layers of the Network

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Network TypesPeer to PeerWindows 98/2000Windows for WorkgroupsClient Server (server-based)Windows NTNovellUnix / Linux

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Peer to PeerNo centralized controlAct as both client & serverUser controls access to machineInstitutionalized chaos & security concernsAdding machines slows network down

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Peer to Peer Advantages

Easy to install & configure

Users control individual shared resources

Inexpensive to purchase & operate

No Network Administrator

Best for 10 or fewer users

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Peer to Peer Disadvantages

Security for only a single resource at a timeUsers may need to know many passwordsIndividual machine backupsSpeed decreases while sharing No central location/access of data

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Server Based Networks

Server is the key to this type

Centralized control of resources

Utilize faster processors

More memory

Extra peripherals

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Server Security

Physical access to the serverSpecialized sentry serversDomain modelAccount namesPasswordsFirewalls

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Server Based Advantages

Central security/ accounts/ access

Simplify network administration

Powerful/ efficient access to resources

Single password for each user

Best for high use, user, networks

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Server Based Disadvantages

Server failure results in unusable network

Server failure results in loss of resources

Expert staff to manage increases cost

Dedicated hardware increases cost

Dedicated software increases cost

All disadvantages may be overcome with $$$

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Hybrid Networks

Combination networks

Windows 95/98/2000

Windows NT Server/Server 2000

Windows NT Workstation

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Server Hardware Requirements

High Speed Drives –Mirrored or RAID

512 MB Memory Minimum

High Quality NIC(s)

High-end Processor(s)

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Specialized Servers

Individual services suppliedApplication ServersCommunication ServersDomain Controllers/Directory

ServersFax Servers

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Specialized Servers (cont.)

Mail ServersWeb Servers File & Print Servers

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Application ServersServer side of Client/Server applicationsSupply application services and dataProvide processing servicesMicrosoft SQL Server runs onWindows NT Server

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Communication Servers

Access beyond networks local scopeInbound & outbound resource accessDial in via modemWindows NT server Remote Access Server(RAS) manages dial in network connections

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Domain Controllers/Directory Servers

Locate, store, & secure information about network Allows computers, users, groups, & resources to be combined into domainsDomain access allows single login to all allowed resources

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Fax Servers

Manage network fax trafficReceive incoming telephone faxesDistribute to network usersCollect outgoing network faxesSend outgoing telephone faxes

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File and Print Servers

File storage & File retrieval

Access to network printers

Applications run locally

Store data on server

Window NT server is capable

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Mail ServersE-mail for network usersAllow local exchange of messagesPermit server based storage of messages Forward user messages to destinationMicrosoft Exchange Server

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Web Servers

World Wide Web (WWW)File Transfer Protocol (FTP)Gopher servicesIntranetsNT Server Internet Information Server (IIS)

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Selecting the Right Network

Budget considerations, number of users?

Physical span of the network?

Specialized servers, services desired?

Internetwork or WAN access?

Future growth?

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Summary

Basic elements to build a network Medium, physical interface, protocolNetworking software-client & server

Basic network typesPeer to PeerServer based

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