Introduction to Networks Networking Concepts IST-200 VWCC 1

What is Networking? Connecting computers to form a Local Area Network ( LAN ) 1

Device Sharing Sharing of: Hardware Software Information 1

A Simple Network 1

Local & Wide Area Networks Early networks were custom built Connecting a dozen computers Only 1 or 2 peripherals Early Ethernet 30 users total span of 601 feet 1

Local Area Network (LAN) A single collection of machines & peripherals Generally less than 1000 computers “Spanned” generally less than 250 meters feet Basic building block for larger networks-Internetworks 1

InterNetworks IntraNetworks A network of networks A networked collection of LANs More than one floor in a business (intranetwork) Multiple buildings Campus environment 1

Wide Area Networks (WAN) Spans miles of distance Two or more separate locations Down the road or across the world Microsoft, Federal Express 1

The Internet A WAN internetwork Millions of machines worldwide The World Wide Web (WWW) 1

Networking Terminology Client/Server relationship Client requests shared resources Server responds & shares resources 1

Networking Terminology 1

Client Server Networks Concentrate CPU power & storage capacity Windows NT Server / Server 2000 Peer to Peer Client/Server role interchanges Windows 95/98/2000/XP 1

Simple Network Needs Medium to carry data Adapter (NIC) Protocol Client / Server Software

Local Network Medium (media) Carries network messages Connects machines together on network Four types: Metallic cable coaxial - dated Twisted pair Fiber optic cable Wireless 1

Network Interface Card (NIC) Physical link between machine & network Connection between machine & medium Also known as network adapter 1

Network Protocols Common set of communication rules Identify ‘oneself” & others on network Interpret signals Begin & end network communication Manage network information exchange 1

Protocol Examples TCP/IP for the Internet IPX/SPX & NWLINK for Novell NetBEUI for Microsoft 1

Windows Client Setup Control Panel Networking Protocols Clients Adapters

Network Software Programs that access the network Network Operating System (NOS) Windows NT Novell NetWare (IntranetWare) Consist of client & server components 1

Network Layers Network Applications ( NOS & client) Instruct network medium Using machines interface (NIC) Address & exchange information To other machines on LAN or WAN 1

Layers of the Network 1

Network Types Peer to Peer Windows 98/2000 Windows for Workgroups Client Server (server-based) Windows NT Novell Unix / Linux 1

Peer to Peer No centralized control Act as both client & server User controls access to machine Institutionalized chaos & security concerns Adding machines slows network down 1

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 1

Peer to Peer Disadvantages Security for only a single resource at a time Users may need to know many passwords Individual machine backups Speed decreases while sharing No central location/access of data 1

Server Based Networks Server is the key to this type Centralized control of resources Utilize faster processors More memory Extra peripherals 1

Server Security Physical access to the server Specialized sentry servers Domain model Account names Passwords Firewalls 1

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 1

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 $$$ 1

Hybrid Networks Combination networks Windows 95/98/2000 Windows NT Server/Server 2000 Windows NT Workstation 1

Server Hardware Requirements High Speed Drives –Mirrored or RAID 512 MB Memory Minimum High Quality NIC(s) High-end Processor(s) 1

Specialized Servers Individual services supplied Application Servers Communication Servers Domain Controllers/Directory Servers Fax Servers 1

Specialized Servers (cont.) Mail Servers Web Servers File & Print Servers 1

Application Servers Server side of Client/Server applications Supply application services and data Provide processing services Microsoft SQL Server runs on Windows NT Server 1

Communication Servers Access beyond networks local scope Inbound & outbound resource access Dial in via modem Windows NT server Remote Access Server (RAS) manages dial in network connections 1

Domain Controllers/ Directory Servers Locate, store, & secure information about network Allows computers, users, groups, & resources to be combined into domains Domain access allows single login to all allowed resources 1

Fax Servers Manage network fax traffic Receive incoming telephone faxes Distribute to network users Collect outgoing network faxes Send outgoing telephone faxes 1

File and Print Servers File storage & File retrieval Access to network printers Applications run locally Store data on server Window NT server is capable 1

Mail Servers for network users Allow local exchange of messages Permit server based storage of messages Forward user messages to destination Microsoft Exchange Server 1

Web Servers World Wide Web (WWW) File Transfer Protocol (FTP) Gopher services Intranets NT Server Internet Information Server (IIS) 1

Selecting the Right Network Budget considerations, number of users? Physical span of the network? Specialized servers, services desired? Internetwork or WAN access? Future growth? 1

Summary Basic elements to build a network Medium, physical interface, protocol Networking software-client & server Basic network types Peer to Peer Server based 1