Chapter 7 Introduction to Networks Ruth Watson Operating

Chapter 7 Introduction to Networks Ruth Watson Operating Systems Concepts 1/e Ruth Watson Chapter 7

Objectives (1 of 2) n Differentiate between a peer-to-peer network and a client server network n Explain the importance of the choice of file system n Differentiate between a client computer and a server n List at least three different server services n Explain the difference between centralized and decentralized administration n Explain the difference between workgroup and domain membership Operating Systems Concepts 1/e Ruth Watson Chapter 7 2

Objectives (2 of 2) n Explain why the NTFS file system is more secure than the FAT file system n Define topology n Describe the four main topologies n Differentiate between a network topology and a network technology n Demonstrate how to configure Local Area Connection properties n Describe the role of the network interface card (NIC) Operating Systems Concepts 1/e Ruth Watson Chapter 7 3

Introduction n Most professionals work in a Networked environment n Security becomes an issue in a networked environment n When designing networks, there are specific guidelines to follow, such as: n When implementing a network, the physical structure includes: q NIC Cards q Cables q Transmission media q Hubs q Type of Network q Switches q File System q Routers q Security Operating Systems Concepts 1/e Ruth Watson Chapter 7 4

Important Terms to Understand n n n Attenuation Bus Client/server Cluster Ethernet FAT 32 File system Hub LAN (local area network) MAN (metropolitan area network) Media Network Operating Systems Concepts 1/e n n n NIC (network interface card) NOS (network operating system) NTFS Peer-to-peer Repeater Ring Router Slack space Star Switch Token Ring WAN (wide area network) Ruth Watson Chapter 7 5

Network Scope n Local Area Network (LAN) q q n Usually confined to a building or an office floor Wide Area Network (WAN) q q n Small Network Two or more LANs connected together The Internet is an example Metropolitan Area Network (MAN) q Covers a large area, such as a city Operating Systems Concepts 1/e Ruth Watson Chapter 7 6

Types of Networks - Peer-To-Peer Operating Systems Concepts 1/e n Good for small environments, usually up to 10 computers n No dedicated network administrator n Each computer must have specific permissions assigned n Sharing resources can become a problem if the computer with the resource is down n Security is a serious issue Ruth Watson Chapter 7 7

Types of Networks - Client/Server n A server has a special Network Operating system (NOS) to help provide resources to multiple users n Client/Server environments usually have one or more network administrators n Problems can include access, security, and integrity of data n Backups are needed in this environment Operating Systems Concepts 1/e Ruth Watson Chapter 7 8

Types of Networks - Home Networks n Operating Systems Concepts 1/e Home networks are becoming more popular q Typically peer-to-peer q Set up is fairly easy n A router keeps track of all the computers inside the home network n Computers are configured with fake IP addresses that allow them to communicate Ruth Watson Chapter 7 9

Centralized vs. Decentralized n Centralized q Client/Server Environment n Decentralized n Resources are on server Peer-to-Peer Environment n Backup is easier n n Profiles are easy to keep track of Resources are spread out n There are no profiles Operating Systems Concepts 1/e q Ruth Watson Chapter 7 10

Workgroup vs. Domain n Workgroup q Peer-to-Peer Environment n Domain q Client/Server Environment n Effective for small environments n Effective for larger environments n Security is a problem n Network administrator has control Operating Systems Concepts 1/e Ruth Watson Chapter 7 11

Files Systems n A file system keeps track of files and folders q q DOS uses FAT (File Allocation System Windows 2000 uses NTFS (New Technology File System) Operating Systems Concepts 1/e Ruth Watson Chapter 7 12

Choosing a File System n Files systems keep track of files and folders n There are several file systems to choose n A file system determines how files can be named and length of file names n Each operating systems has its own file system q LINUX: ext 2 or ext 3 q Windows 2000: NTFS or FAT 32 Operating Systems Concepts 1/e Ruth Watson Chapter 7 13

Security Operating Systems Concepts 1/e n How much security you need helps to determine a file system n FAT/FAT 32 is good on stand alone computers n NTFS should be used on networks Ruth Watson Chapter 7 14

Network Topology - Bus n Computers are daisy chained together in a linear bus q q q q Commonly used in the 1980’s Least expensive Easiest to setup Uses coax cable Data packets are sent along the coax cables All computers hear data sent out A BNC connector is used for the NIC card If there is a break in the computer, the other computers are disturbed Operating Systems Concepts 1/e Ruth Watson Chapter 7 15

Network Topology - Star n Computers are concentrated into a star pattern using hubs or switches q q q q q Operating Systems Concepts 1/e Most LANs use Star topology Uses Category 5 cable (cat 6 is on the way) Cat 5 cable uses an RJ-45 connector for the NIC card Easy to install Not that expensive Hubs broadcast data to all devices Switches can be used instead of hubs Switches can help segment data traffic but are more expensive If there is a break in the cable, it does not disturb the other computers Ruth Watson Chapter 7 16

Network Topology - Ring n Not used as often as the Star q Uses different hardware q More expensive q Complex to install q Best at passing data with less collisions Operating Systems Concepts 1/e Ruth Watson Chapter 7 17

Network Technology - Ethernet n n n Operating Systems Concepts 1/e Ethernet was developed by Bob Metcafe and D. R. Boggs at the Palo Alto Center in the early 1970’s Multiple cables and protocols can be used with Ethernet Different networks can be connected, such as: q Windows q Macintosh q Novell q Unix Ruth Watson Chapter 7 18

Network Technology - Token Ring n Token Ring uses a different access method n Only one device transmits at a time n Each device checks to see if the data is for them n Fewer collisions Operating Systems Concepts 1/e Ruth Watson Chapter 7 19

Protocols n Protocols are agreed upon rules that networked devices use to communicate n Different organizations came up with different protocols q Operating Systems Concepts 1/e TCP/IP resolved issues and enabled all computer platforms to communicate Ruth Watson Chapter 7 20

LAN Components n LAN components include: q Repeaters n q Hubs n q Act as a concentrator to connect several computers Switches n q Used to amplify data signals due to attenuation Intelligent hubs that segment traffic to avoid collisions Routers n Must have to be able to access the Internet Operating Systems Concepts 1/e Ruth Watson Chapter 7 21

Network Interface Card (NIC) Operating Systems Concepts 1/e n NIC enables computers to communicate through a unique media access control (MAC) address n The MAC is burned in at the factory Ruth Watson Chapter 7 22

Summary n You don’t have to be a technology specialist to network your home n Networks range from very small to very large n A server has a special operating system on it that allows multiple users to log in at the same time n Peer-to-Peer networks require no server, but security is an issue n A Client/Server network must have at least one dedicated server and a network administrator n There are four ways to connect your network: bus, star, ring, or hybrid n Protocols are rules that allow computers and other devices to communicate n The most common protocol is TCP/IP Operating Systems Concepts 1/e Ruth Watson Chapter 7 23

Questions? Operating Systems Concepts 1/e Ruth Watson Chapter 7 24