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Networks, Network operating systems and Databases. Networking - Basics. Network defined The difference between Standalone and networked Systems Advantages of networking Disadvantages of networking Why use network To share information To Share hardware and software
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Networking - Basics • Network defined • The difference between Standalone and networked Systems • Advantages of networking • Disadvantages of networking • Why use network • To share information • To Share hardware and software • Centralizing administration
Types of networks • Classification based on geographical area • LAN • WAN
Local Area Networks • Limited geographic area • High speed and error free data transmission • Not expensive
Wide Area Networks • Connects computers over states, countries etc., • Unlimited geographical coverage • More sophisticated • Connects LANs and MANs • Expensive technology
Network configuration • Classification based on how computers behave in a network • Two classifications are • Peer-to-Peer network • Server based network
Peer-to-Peer network • Nodes provide and request services • User in each node administers resources • No extra investment • Easy to setup • Very weak security • Additional load on nodes
Server based network • Designated computer to administer • Resources centralized • Supports larger networks • Strong security • Expensive
Topologies - Physical • Refers to physical arrangement of • Computers • Cables • Other components
Types of topologies • Bus • Star • Ring • Mesh
Bus topology • Linear connection • Simple installation • Passive in nature • Data travels from one end to other • Slow signal transfer • Failure of one computer does not affect • Extensions weaken the signal
Star topology • Connected to a central hub • Easier administration • Difficult to install • High cable cost • Hub failure fails the network
Ring Topology • Circular connection • Signals travel in one direction, through each computer • Failure of one computer affects entire network • Difficult to troubleshoot
Star bus topology • Combination of several stars • Augments systems in network • Failure of hub/s fails the network
Network hardware • Hub • Cables • Connectors • Switches • Routers
Hub • Standard component in Star topology • Types • Active, Passive • Manageable • Easier administration • Centralized monitoring of network
Cables • Wires the LAN, usually • Transmit signals through network • Different cable considerations according to need • Types • Co-axial • Twisted Pair • Fiber-optic
Co-axial cable • Most trusted in earlier networks • Carries data as electromagnetic signals • Good resistance against interference
Twisted pair • Pair of insulated copper wires • Types • Shielded(STP) • Unshielded(UTP) • UTP common in LAN • Max. cable length – 100 meters
UTP categories • Category 1 – Used as telephone cables – carry voice(Two pairs) • Category 2 – Data transmission up to 4 mbps(Four pairs) • Category 3 – Data transmission up to 16 mbps(Four pairs) • Category 4 – Data transmission up to 20 mbps(Four pairs) • Category 5 – Data transmission up to 100 mbps(Four pairs) • Category 6 – Data transmission above 100 mbps (Four pairs)
Fiber optic cables • Core – cylinder of glass • Not subject to interference • Transfer rate – more than 100 mbps • Expensive
Connectors for UTP • RJ – 11 and RJ – 45 • RJ11 in telephone cables – 4 cable connections • RJ45 in LAN cables – 8 cable connections
Cable connection method Used to connect a system to hub or switch in LAN
Network adapter card • Prepares data from computer for network and sends • Receives data from network and translates for computer
Network adapter considerations • Connected to expansion slot on motherboard • Has memory for storage of data before transmission • Current adapters come with RJ-45 connectors • Driver software to be loaded on connection • Requires configuration for network participation
Using IP address • Two methods • Static addressing • Using DHCP • Two components • Network ID • Host ID • 3 classes • Class A networks • Class B networks • Class C networks
Network troubleshooting • In case of problems • Check Physical connection first • Check power supply in the hub • Check sample packet transfer • Check configuration
Network operating systems • Co-ordinates hardware and software • Ties together all computers and peripherals • Provides security by controlling access to resources and peripherals shared • Manages users
Network operating systems available • Windows NT • Windows 2000 & Windows Server 2003 • Netware from Novell • Unix • Apple Macintosh
Shares • Sharing allows access to resources over network • Folders and devices are directly shared; not files or programs • Permissions for access can be assigned to users and groups • Level of permission can be varied
Local User Accounts • Enable users to log on and access resources on a specific computer Domain User Accounts • Enable users to log on to the domain to gain access to network resources • Reside in Active Directory User accounts Built-in User Accounts • Enable users to perform administrative tasks or gain temporary access to network resources • Reside in SAM (local built-in user accounts) • Reside in Active Directory (domain built-in user accounts)
User Access issues • Domain Logon • Access verification • Grant/deny access
Password Security • Do not allow blank passwords • Assign a Password for the Administrator Account • Determine Who Has Control over Passwords • Educate Users on How to Use Passwords • Avoid obvious associations, such as a family name • Use long passwords • Use a combination of uppercase and lowercase characters
Domain User Properties • Set logon hours according to requirements • Set expiration for User accounts • Specify the Computers from Which a User Can Log On • Domain users can log on at any computer in the domain, by default • Domain users can be restricted to specific computers to increase security
Installing network printer • Involves • Installing the printer • Configuring • Sharing • Administering
Disk Management Basics Disk Types Dynamic disks Basic Disks C D E F Partitions Volumes
Database management and SQL Server • Overview of Databases • Data is a collection of raw facts • Database is a collection of data stored inside tables • Provides centralized control of data • Relational database management • Advantages • Reduces data redundancy • Can be shared among many users • Security around access can be implemented
RDBMS in the market • Microsoft SQL Server • Oracle • Sybase
Evolution of SQL Server • The Beginning • SQL 6.5 • SQL 7.0 • SQL 2000 • SQL 2005
SQL Server 2000 • It is a relational database management system • It can support up to 32 processors and 64 GB memory • Can handle upto 6,88,220 transactions per minute • Comes with upgrade utility • Scalable • Maintains relationship among data stored inside database • Comes with features like replication, English query
Integration with Windows 2000 OS • Developed for Windows 2000 environment • Can also integrate with Win 9x/NT • Uses features of Windows 2000 like • Active Directory • Security • Event Viewer
Components of SQL Server architecture • Supports client-server architecture • Server takes action based on requests from clients
Editions of SQL Server 2000 • Standard • Personal • Enterprise
Editions of SQL Server 2005 • Standard • Backward compatibility tool(client) • Enterprise
SQL Server Enterprise Manager/Management studio • Used to perform administrative tasks • Tasks performed are • Manage security • Manage databases • Manage backups • Follow up events
Backup of database - Overview • Backup is a copy • Stores copy in another media like • Local Hard disk • Tape disk • Network drive
Backup of database - Need • Hardware failure • Natural calamities • Virus attacks • Theft • Accidental loss due to wrong queries
Backup types • Full or complete • Differential • Transaction log
Backup strategy • Good strategy helps restore data with minimum down time • Minimizes permanent loss of data • A good plan should involve minimum shut down of operations for backup • Good strategy should put the system back to what it was before failure
This completes the unit Thank you