XTR Consulting: A SOHO Network with Dedicated Servers

Transcription

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 Figure 1b-1: XTR Consulting s Network Versus Pat Lee s Network 2 Number of Client PCs Pat Lee s Home Network 2 PCs Plus a Notebook PC XTR Consulting s Small Office Network 17 User PCs File Service Peer-to-Peer Dedicated Server Systems Administration Print Service Peer-to-Peer Print Servers Access Router and Ethernet Switch Combined Separate Boxes Access Router Has Firewall

2 Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers 3 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 Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued 4 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

3 Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued 5 Server Technology PC Servers and Network Operating Systems (NOSs) NOS for PC Server Network operating systems (NOSs) are server operating systems that have more functions and reliability than client operating systems Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued 6 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

4 Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued 7 Server Technology Mainframe Servers Faster, more reliable, and more expensive than workstation servers Require a large systems programming staff Systems Programmers Mainframe Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued 8 Server Technology Server Farms Group of PC servers or workstation servers HTTP-1 HTTP-2 HTTP-3 FTP-1

5 Figure 1b-3: Server Farm with Load- Balancing Router 9 Load-balancing router selects host on the basis of load and applications supported by the host HTTP-1 HTTP-2 HTTP-3 FTP-1 Load-Balancing Router Figure 1b-3: Server Farm with Load-Balancing Router, Continued 10 Benefits of Server Farms Scalability Add server capacity as needed Reliability If one server fails, system continues to work with slightly less processing power

6 Figure 1b-4: Popular PC Server Network Operating Systems (NOSs) 11 Microsoft Windows Server LINUX Novell NetWare Ease of Learning Very Good Poor Good Ease of Use Very Good Poor Good Reliability Very Good in recent versions Excellent Very Good Standardization Availability of Device Drivers Purchase Price Excellent Excellent Moderate Poor (Many Distributions) Poor Low or Free Excellent Very Good Higher than Windows Management Labor Moderate High Higher than Windows Figure 1b-5: Microsoft Windows 2003 Server User Interface Can Run Client Windows Programs 1. Start Button 2. All Programs 3. Explorer, Recycle Bin

7 Figure 1b-5: Microsoft Windows 2003 Server User Interface, Continued 2. Or Via 13 Start / Manage Your Server (Wizard) 1. Most Administrative Tools Are Accessed Via Start / Administrative Tools (Individual Tools) Figure 1b-6: Microsoft Management Console 14 Individual tools are organized as Microsoft Management Consoles (MMCs), which have a fixed basic organization, to give ease of learning 3. 4.

8 Figure 1b-7: Managing Access Permissions 15 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 Figure 1b-7: Managing Access Permissions, Continued 16 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

9 Figure 1b-7: Managing Access Permissions, Continued 17 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 Figure 1b-7: Managing Access Permissions, Continued 18 Microsoft Windows Permissions Full Control Is an omnibus permission. It is equal to all of the above permissions

10 Figure 1b-7: Managing Access Permissions, Continued 19 Unix Permissions Read (only) Write Execute (run programs) Figure 1b-7: Managing Access Permissions, Continued 20 Windows List folder contents Read Write Modify Read and Execute Full Control Unix Read Write Execute Granular for precise access control Crude access control

11 Figure 1b-7: Managing Access Permissions, Continued 21 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 control Inflexible access control Figure 1b-7: Managing Access Permissions, Continued: Recap 22 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

12 Figure 1b-7: Managing Access Permissions, Continued 23 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 Figure 1b-7: Managing Access Permissions, Continued 24 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 Ochoa Write In Marketing Directory Group: Marketing Write In Marketing Directory Chen Williams

13 Figure 1b-7: Managing Access Permissions, Continued 25 Reducing the Work of Assigning Permissions Inheritance: permissions are inherited by subdirectories to reduce permission assignment work Group Everyone Gets Read Read Public Directory Read Read Policies Maps Training Read Personnel Discipline No Inheritance Figure 1b-8: Assigning Directory Permissions in Windows Server Selected Directory User or Group (Power Users) 4. Power User Permissions 5.

14 Figure 1b-9: File Service for Data Files 27 File Server with Program and Data Files Save Retrieve No Access User A User B User C Figure 1b-10: File Server Program Access Program Stored on File Server File Server 2. Program Downloaded to Client PC When Called Client PC 3. Program Executed on Client PC

15 Figure 1b-11: File Server Program Access and Program Installation Program is installed only once, on a file server File Server 4. This process greatly reduces software installation and upgrading costs 2. Program downloaded to Client PCs when called Client PC Client PC 3. No need to install on each client PC 3. No need to install on each client PC Figure 1b-12: Print Server Operation 30 Hub or Switch Parallel or USB Cable 1-2 meters UTP up to 100 m Print Server Printer Client PC 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

16 Figure 1b-12: Print Server Operation, Continued 31 Hub or Switch Parallel Cable 1-2 meters UTP up to 100 m Print Server Printer Client PC UTP up to 100 m Some high-end printers are network-capable, with built-in print servers Connect directly to the switch Network- Capable Printer (with built-in print server) Figure 1b-12: Print Server Operation, Continued 32 Hub or Switch Parallel Cable 1-2 meters UTP up to 100 m Print Server Printer Client PC UTP up to 100 m File servers can act as print servers; But file servers are rarely near users File Server acting as Print Server 1-2 m Printer

17 Figure 1b-13: Print Server (Photo) 33 RJ-45 Port Power Supply Port RJ-45 Cord to Switch Port Parallel or USB Port Parallel or USB Cable to Printer Topics Covered 34 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

18 Topics Covered 35 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 Topics Covered 36 File Servers Sharing data files File server program access Print Servers Between the switch and the printer