Local Area Networks: Software and Support Systems

Transcription

1 Local Area Networks: Software and Support Systems Chapter 8 Learning Objectives After reading this chapter, you should be able to: Identify the main functions of operating systems and network operating systems and distinguish between the two Identify the basic features of Novell NetWare, Windows NT/2000/2003, Unix, Linux, and Mac OS X Server network operating systems Compare and contrast the Novell NetWare, Windows NT/2000/2003, Unix, Linux, and Mac OS X Server network operating systems Recognize the importance of the network server and the different types of network servers available Identify the different levels of RAID Identify common examples of network utility software and Internet software Enumerate the various components of software licenses Identify the different types of support devices commonly found on local area networks Chapter Outline 1. Introduction 2. Network Operating Systems 3. Current Network Operating Systems a. Novell NetWare b. Microsoft Windows c. Unix d. Linux e. Mac OS X Server f. Summary of network operating systems 4. Network Servers a. Client/server networks vs. peer-to-peer networks

2 5. Network Software Support a. Utilities b. Internet software 6. Software Licensing Agreements 7. LAN Support Devices 8. LAN Software In Action: A Small Company Makes a Choice a. Primary uses of current network b. Network maintenance and support c. Cost of the NOS d. Any unique hardware choices affecting NOS decision e. Single location or multiple locations f. Political pressures affecting decision g. Final decision 8. Wireless Networking In Action: Creating a Wireless LAN for Home 9. Summary Lecture Notes Introduction This chapter will conclude the discussion of local area networks by introducing the software that runs the local area network and that runs on a local area network. We will concentrate on two basic areas: network operating systems and supporting software. The network operating system provides user accounts with password protection, controlled access to network resources, and services to help use and administer the network. Local area network operating systems, much like the hardware that supports them, continue to evolve into more powerful and elaborate tools every day. Network support software is essential since it is the reason users use networked workstations. The more common products include antivirus software, antispam software, backup software, security software, and network-monitoring software. Network Operating Systems A network operating system is a large, complex program that can manage the resources common on most local area networks, in addition to performing the standard operating system services. The resources a network operating system must manage include one or more network servers, multiple network printers, one or more physical networks, and a potentially large number of users directly connected to the network and sometimes remotely connected. The resources a network operating system must manage include one or more network servers, multiple network printers, one or more physical networks, and a potentially large number of users directly connected to the network and sometimes remotely connected.

3 Current Network Operating Systems A network operating system supports many functions that we, as users, normally take for granted. Having an understanding of these basic functions allows you to examine actual network operating systems more closely, compare these products by how well each supports the basic functions, and evaluate their strengths and weaknesses. Having mastered the basic functions, let s turn our attention to several of the more popular network operating systems on the market: Novell NetWare, Windows NT/2000/2003/2008, Unix, Linux, and Mac OS X Server. Network Support Software Even though the network operating system is clearly the most important piece of software on a local area network, the operating system cannot work alone. Two additional areas of local area network software that work with and support the network operating system are: utilities (software programs that support one or more functions that help keep the network running at optimal performance and that operate in the background) and Internet software (programs that allow access to the Internet). Software Licensing Agreements The licensing agreement that accompanies a software product is a legal contract and describes a number of conditions that must be upheld for proper use of the software package. One of the most important conditions that affects most users is software installation and use. When a software package is sold, it is usually intended for a particular type of installation, referred to as the user license. LAN Support Devices A local area network is composed of many pieces, both software and hardware. The chapter, up to this point, has introduced the software of local area networks network operating systems, utility, application and software tools, and software licenses. The hardware side of local area networks contains many different types of devices. In Chapter 7, bridges, routers, and switches the hardware that interconnects devices on the network were covered in detail. Servers were introduced because they are becoming an interconnection point within a network and often contain switch and router hardware. Let s look at a number of other network support devices, including uninterruptable power supplies, tape drives, printers, media converters, and workstations, that you may encounter on a typical local area network. LAN Software In Action: A Small Company Makes a Choice This In Action example continues the In Action from the two previous chapters. Hannah must decide which network operating system to incorporate. In order to make this decision properly, she considers several issues, including primary uses of current system, cost, and local versus remote access.

4 Quick Quiz 1. What is a client/server system s primary function? To accept requests (such as database queries or file retrieval queries) and return results 2. Enumerate the strengths and weaknesses of NetWare, Windows NT/2000/2003, Unix, Max OS X Server, and Linux. Strengths include: NetWare is an excellent file server. Windows NT is an excellent application server providing client/server capabilities to a wide range of applications. Unix and Linux give power, stability, and flexibility by providing a wide range of services to many different types of network applications. Mac OS X Server is Linux-based, robust, and powerful. 3. Why does a software company need a software license? To protect itself from people or companies that make unlimited copies of the software 4. Compile a list of LAN support devices. Backup, UPS, printers, media converters, workstations, etc. Discussion Topics 1. Should software licenses be dropped completely? 2. If software licenses should be allowed to remain, shouldn t the company provide the source code? 3. Can the number of problems that plagues Windows NT/2000/2003 be attributed to its newness? Its size and complexity? That so many people use it, making it the number one target? Teaching Tips 1. Do you have access to a couple different NOSs? Can you demonstrate them in class or give simple assignments on each? 2. Talk about the latest copyright code. Discuss how copyright compares to patents. 3. Using an actual system at school, identify all application network software tools and LAN support devices.

5 Solutions to Review Questions 1. List the six basic functions of an operating system. Manages all programs and resources, handles I/O, security, memory management, storage management, communicates status of system 2. What separates a multitasking operating system from a non-multitasking operating system? Multitasking can run multiple processes at the same time. 3. List the primary differences between a network operating system and an operating system. NOS manages network servers, printers, multiple networks, and potentially large numbers of local and remote users. 4. What is an application program interface? The software that provides a connection between the system and an application 5. What are the basic functions of a network operating system? Support server and printer operations; allow users to log on; user accounting procedures; all normal operating system functions (disk/memory/cpu/peripheral management) 6. What is meant by disk mirroring? Splitting data over multiple disk drives 7. What is an organizational unit? A container that holds other organizational units or leaf objects 8. What is the function of NetWare s NDS? To manage all files, users, and resources in a powerful and efficient manner 9. What are the primary features of NetWare? 4: NDS; 5: native TCP/IP; 6: run network client from any Internet accessible workstation 10. What are the main advantages of Windows 2000 over NT version 4? More powerful, flexible, and manageable

6 11. What are the differences between Windows 2003 and Windows 2000? Administrative improvements, server clustering, IPv6 support, better security 12. What is the function of Windows Active Directory? Same as NDS for NetWare 13. What are the strengths of Unix? Fast, powerful, popular, stable 14. List the reasons for Linux s popularity. Free, stable, fast 15. What are the disadvantages of Linux? No one company supports the code. 16. What are the advantages and disadvantages of Mac OS X Server? Advantages: robust, powerful, stable Disadvantage: not widely used 17. What is the importance of a network server? Holds the server portion of the network operating system; can hold global data sets 18. What different kinds of network servers are available? Server boxes, server blades, server appliances 19. What are the different levels of RAID, and what does each do? RAID 0: striping RAID 1: mirroring RAID 3: striping with error checking on separate disk RAID 5: striping with error checking stored with data 20. What are the issues often stated in a software license agreement? Use issues, no decompiling, no copying or modifying, upgrade options

7 21. List the types of software license agreements. Single user single station, single user multiple station, interactive user, network server, site, corporate 22. What are the nine most common groups of network utility software? Antivirus, antispam, antispyware, backup, crash protection, network-monitoring, remote access, security assessment, uninstall 23. What are the primary functions of an Internet Web page server? To accept requests from clients for Web pages and to return the Web pages to the clients 24. What are the different types of hardware support devices for local area networks? Bridges, routers, switches, hubs, servers, UPS, tape drives, printers, media converters, modems, workstations Suggested Solutions to Exercises 1. In a client/server system, a client transmits a request to a server, the server performs a processing operation, and the server returns a result. List all the possible things that can go wrong with transmission in this scenario. Request gets lost, client waits. Request gets temporarily lost, client sends another, then two requests arrive at server. Results from server are lost. Results from server are temporarily lost, then client sends request again, getting two sets of results. Client crashes before results come back. Server crashes before request arrives or after results start their way back. 2. What are the primary advantages of NetWare version 4 over NetWare version 3? Are there any disadvantages? Version 4 uses NDS, which is a powerful, one login, file and resource support system. A disadvantage of version 4 might be complexity, learning curve of network administrator, or setting up NDS tree incorrectly. 3. You want to create a local area network that protects the contents of the network server s hard disks from disk crashes. List all the different techniques for providing this protection that have been presented thus far. Disk mirroring, disk duplexing, hot-swappable disks, crash protection software

8 4. What is the main structure (container) used when designing a Windows NT network? The domain 5. Windows 2000/2003/2008 uses Active Directory for its directory service, and NetWare uses NDS. How are the two directory services alike? How are they different? Both use tree structures and both allow an administrator to manipulate individual objects or container objects that represent collections of devices and individuals. Active Directory allows forests, while NDS does not. 6. When using either Novell s NDS or Windows Active Directory, an administrator can control resources on a macro level. Explain what controlling resources on a macro level means and show an example. Create a structure, such as Accounts Receivable, which contains many users. Then assign access rights and privileges to that structure. 7. You are working for a company that has three divisions: marketing, research, and sales. Each division has many employees, each with their own workstation. Each division also has its own network server and a number of high-quality printers. Draw the Windows NT domain diagram, Windows 2000 Active Directory diagram, and NetWare NDS diagram that support this company s network structure. 8. In what ways are Unix and Linux similar? In what ways are they different? They both have text-based interfaces (as well as windows-like interfaces), and they are robust, powerful, and very stable. One big difference is that Linux is free. 9. Why is the stability of Linux so high when compared to other network operating systems? It is a very simple, clean design compared to other operating systems. 10. The problem with antivirus software is that new viruses are being created every day. If you have antivirus software installed on your machine or on your network, how do you keep your software up to date? Go to the virus Web site and download the latest software upgrades 11. How does a single-user-single-station software license differ from a single-usermultiple-station license? Does one have an advantage over another in the business world? In the home computer world? Single-user-single-station means load this software on one and only one computer.

9 12. What kind of software applications might a company consider as likely candidates for a site license? Word processors, spreadsheets, databases, programs, and other productivity tools 13. Consider the following software licensing scenario: Office Suite 1 costs $229 per singleuser-single-station license, while Office Suite 2 costs $299 per interactive user license. You have 200 users on your network, and you estimate that at any one time only 60 percent of your users will be using a suite application. Determine the best license solution. At what level of interactive use will the cost of the interactive user license break even with that of the single-user-single-station licenses? If you use single-user-single-station software, you will need a copy for every workstation, so 200 times $229 equals $45,800. If you use the interactive user license software, you will only need 60 percent of 200 users (120) licenses. 120 times $299 equals $35,880. The interactive user license software would be less expensive. The break-even point is 154 concurrent users (154 times $299 equals $46,046). 14. Is a thin client computer more advantageous in a corporate setting or in a user s home? Explain. It s more advantageous in a corporate setting. Corporate users may not need a full machine with all the software and disk storage. Thinking Outside the Box 4. Any workstation operating system will support networking Windows XP, Mac OS X, and most versions of Linux.