1. XTR Consulting: A SOHO Network with Dedicated Servers Chapter 1b Panko’s Business Data Networks and Telecommunications, 5 th edition Copyright 2005 Prentice-Hall

2. 2 Figure 1b-1: XTR Consulting’s Network Versus Pat Lee’s Network Pat Lee’s Home Network XTR Consulting’s Small Office Network Number of Client PCs2 PCs Plus a Notebook PC 17 User PCs File ServicePeer-to-PeerDedicated Server Systems Administration Access Router and Ethernet Switch CombinedSeparate Boxes Access Router Has Firewall Print ServicePeer-to-PeerPrint Servers

3. 3 Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers Peer-to-Peer Networks Clients serving other clients Inexpensive--no need to purchase a dedicated server Operational problems for other users if a user PC is turned off or crashes Poor security: No password or shared password for shared directories

4. 4 Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued Server Technology PC Servers and Network Operating Systems (NOSs) Standard PC architectures but More RAM Large and fast hard disk drives Redundant power supplies and fans Multiple processors (multiprocessing) PC Server

5. 5 Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued Server Technology PC Servers and Network Operating Systems (NOSs) Network operating systems (NOSs) are server operating systems that have more functions and reliability than client operating systems NOS for PC Server

6. 6 Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued Server Technology Workstation Servers Fast (and expensive) custom microprocessors for an expensive computer Unix Extremely reliable Difficult to learn Not standardized Unix Sun Workstations Server

7. 7 Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued Server Technology Mainframe Servers Faster, more reliable, and more expensive than workstation servers Require a large systems programming staff Systems Programmers Mainframe

8. 8 Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued Server Technology Server Farms Group of PC servers or workstation servers HTTP-1HTTP-2HTTP-3FTP-1

9. 9 Figure 1b-3: Server Farm with Load- Balancing Router Load-Balancing Router HTTP-1HTTP-2HTTP-3FTP-1 Load-balancing router selects host on the basis of load and applications supported by the host

10. 10 Figure 1b-3: Server Farm with Load-Balancing Router, Continued Benefits of Server Farms Scalability Add server capacity as needed Reliability If one server fails, system continues to work with slightly less processing power

11. 11 Figure 1b-4: Popular PC Server Network Operating Systems (NOSs) Microsoft Windows Server LINUXNovell NetWare Ease of Learning Very Good PoorGood Ease of UseVery Good PoorGood Reliability Very Good in recent versions ExcellentVery Good Standardization Availability of Device Drivers Purchase Price Excellent Moderate Poor (Many Distributions) Poor Low or Free Excellent Very Good Higher than Windows Management Labor ModerateHigh Higher than Windows

12. 12 Figure 1b-5: Microsoft Windows 2003 Server User Interface 3. Explorer, Recycle Bin 4. Can Run Client Windows Programs 1. Start Button 2. All Programs

13. 13 Figure 1b-5: Microsoft Windows 2003 Server User Interface, Continued 1. Most Administrative Tools Are Accessed Via Start / Administrative Tools (Individual Tools) 2. Or Via Start / Manage Your Server (Wizard)

14. 14 Figure 1b-6: Microsoft Management Console 3. 4. Individual tools are organized as Microsoft Management Consoles (MMCs), which have a fixed basic organization, to give ease of learning

15. 15 Figure 1b-7: Managing Access Permissions Accounts Have usernames and passwords Accounts are assigned permissions in directories Whether the account holder can go to a directory at all What the account holder can do in the directory if permitted to go there

16. 16 Figure 1b-7: Managing Access Permissions, Continued Microsoft Windows Permissions No Permissions Cannot even see the directory List Folder Contents Allows the account owner to see the contents of a folder (directory) Read Read-only access. Without further permissions, the account owner cannot change the files

17. 17 Figure 1b-7: Managing Access Permissions, Continued Microsoft Windows Permissions Write Edit the contents of files Modify Gives additional permissions to act upon files, for example the permission to delete a file, which is not included in Write Read and Execute Account can run a program

18. 18 Figure 1b-7: Managing Access Permissions, Continued Microsoft Windows Permissions Full Control Is an omnibus permission. It is equal to all of the above permissions

19. 19 Figure 1b-7: Managing Access Permissions, Continued Unix Permissions Read (only) Write Execute (run programs)

20. 20 Figure 1b-7: Managing Access Permissions, Continued Windows List folder contents Read Write Modify Read and Execute Full Control Granular for precise access control Unix Read Write Execute Crude access control

21. 21 Figure 1b-7: Managing Access Permissions, Continued Windows can assign different permissions for a file or directory to Many different individual accounts Many different group accounts Unix can only assign different permissions for a file or directory to The owner One group Everyone else Flexible access controlInflexible access control

22. 22 Figure 1b-7: Managing Access Permissions, Continued: Recap Windows 6 major permissions Can assign different permissions to many individuals and groups Highly flexible Unix Only 3 major permissions Can only assign different permissions to the owner, one group, and the rest of the world Highly inflexible

23. 23 Figure 1b-7: Managing Access Permissions, Continued Administrator Account in Windows Necessary for systems administration Systems administration is the management of one or more servers Not necessarily all servers Dangerous in terms of security Has all permissions in all directories Comparable account in Unix is root

24. 24 Figure 1b-7: Managing Access Permissions, Continued Reducing the Work of Assigning Permissions to All Accounts in All Directories Groups Assign permissions to groups; all group members receive the permission Faster than assigning permission to individuals Group: Marketing Write In Marketing Directory Ochoa Chen Williams Write In Marketing Directory

25. 25 Figure 1b-7: Managing Access Permissions, Continued Reducing the Work of Assigning Permissions Inheritance: permissions are inherited by subdirectories to reduce permission assignment work Public Directory TrainingMapsPoliciesPersonnelDiscipline Group Everyone Gets Read Read No Inheritance

26. 26 Figure 1b-8: Assigning Directory Permissions in Windows Server 2003 1. Selected Directory 3. User or Group (Power Users) 4. Power User Permissions 5. 2. 6.

27. 27 Figure 1b-9: File Service for Data Files Save Retrieve User AUser BUser C No Access File Server with Program and Data Files

28. 28 Figure 1b-10: File Server Program Access 1. Program Stored on File Server File Server 2. Program Downloaded to Client PC When Called 3. Program Executed on Client PC

29. 29 Figure 1b-11: File Server Program Access and Program Installation 2. Program downloaded to Client PCs when called 1. Program is installed only once, on a file server File Server Client PC 3. No need to install on each client PC 3. No need to install on each client PC 4. This process greatly reduces software installation and upgrading costs

30. 30 Figure 1b-12: Print Server Operation Hub or Switch Client PC UTP up to 100 m Print Server Printer Parallel or USB Cable 1-2 meters Print server feeds print jobs to the printer Print server connects to printer via parallel or USB cable, so only 1-2 meters from the printer Print server connects to port on switch via UTP, so maximum distance to switch is 100 meters

31. 31 Figure 1b-12: Print Server Operation, Continued Hub or Switch Client PC Network- Capable Printer (with built-in print server) UTP up to 100 m UTP up to 100 m Print Server Printer Parallel Cable 1-2 meters Some high-end printers are network-capable, with built-in print servers Connect directly to the switch

32. 32 Figure 1b-12: Print Server Operation, Continued Hub or Switch UTP up to 100 m Client PC Printer File Server acting as Print Server UTP up to 100 m Print Server Printer 1-2 m Parallel Cable 1-2 meters File servers can act as print servers; But file servers are rarely near users

33. 33 Figure 1b-13: Print Server (Photo) RJ-45 Port Parallel or USB Port Power Supply Port Parallel or USB Cable to Printer RJ-45 Cord to Switch Port

34. 34 Topics Covered Dedicated Servers PC servers, workstation servers, and mainframes Server farms and load-balancing routers NOSs for PC servers: Windows Server, Linux (a version of Unix), and NetWare

35. 35 Topics Covered Accounts, usernames, and permissions Windows versus Unix permissions Server farms and load-balancing routers NOSs for PC servers: Windows Server, Linux, and NetWare Groups and automatic inheritance

36. 36 Topics Covered File Servers Sharing data files File server program access Print Servers Between the switch and the printer