XTR Consulting: A SOHO Network with Dedicated Servers

Chapter 1b

Panko’sBusiness Data Networks and Telecommunications, 5th editionCopyright 2005 Prentice-Hall

2Figure 1b-1: XTR Consulting’s Network Versus Pat Lee’s Network

Pat Lee’s HomeNetwork

XTR Consulting’sSmall Office Network

Number of Client PCs 2 PCs Plus aNotebook PC

17 User PCs

File Service Peer-to-Peer Dedicated Server Systems Administration

Access Router andEthernet Switch

Combined Separate BoxesAccess Router Has Firewall

Print Service Peer-to-Peer Print Servers

3Figure 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

4Figure 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 andfans

Multiple processors(multiprocessing) PC Server

5Figure 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 forPC Server

6Figure 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

7Figure 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

SystemsProgrammers

Mainframe

8Figure 1b-2: Peer-to-Peer Service Versus Dedicated Servers, Continued

Server Technology Server Farms

Group of PC servers or workstation servers

HTTP-1 HTTP-2 HTTP-3 FTP-1

9Figure 1b-3: Server Farm with Load-Balancing Router

Load-BalancingRouter

HTTP-1 HTTP-2 HTTP-3 FTP-1

Load-balancingrouter selectshost on the

basis ofload and

applicationssupportedby the host

10Figure 1b-3: Server Farm with Load-Balancing Router, Continued

Benefits of Server Farms

ScalabilityAdd server capacity as needed

Reliability If one server fails, system continues to work with

slightly less processing power

11Figure 1b-4: Popular PC Server Network Operating Systems (NOSs)

MicrosoftWindows Server

LINUX Novell NetWare

Ease of Learning

Very Good Poor Good

Ease of Use Very Good Poor Good

ReliabilityVery Good in

recent versionsExcellent Very Good

Standardization

Availability ofDevice Drivers

Purchase Price

Excellent

Excellent

Moderate

Poor (ManyDistributions)

Poor

Low or Free

Excellent

Very Good

Higher thanWindows

ManagementLabor

Moderate HighHigher than

Windows

12Figure 1b-5: Microsoft Windows 2003 Server User Interface

3.Explorer,Recycle

Bin

4. Can Run Client Windows Programs

1.Start

Button2.

All Programs

13Figure 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)

14Figure 1b-6: Microsoft Management Console

3. 4.

Individual toolsare organizedas MicrosoftManagement

Consoles (MMCs),which havea fixed basic

organization, togive ease of

learning

15Figure 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

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

Microsoft Windows Permissions

No PermissionsCannot even see the directory

List Folder ContentsAllows the account owner to see the contents of a

folder (directory)

ReadRead-only access. Without further permissions,

the account owner cannot change the files

17Figure 1b-7: Managing Access Permissions, Continued

Microsoft Windows Permissions Write

Edit the contents of files

ModifyGives additional permissions to act upon files, for

example the permission to delete a file, which is not included in Write

Read and ExecuteAccount can run a program

18Figure 1b-7: Managing Access Permissions, Continued

Microsoft Windows Permissions Full Control

Is an omnibus permission. It is equal to all of the above permissions

19Figure 1b-7: Managing Access Permissions, Continued

Unix Permissions Read (only)

Write

Execute (run programs)

20Figure 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

21Figure 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 control Inflexible access control

22Figure 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

23Figure 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 securityHas all permissions in all directories

Comparable account in Unix is root

24Figure 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

WriteIn Marketing

Directory

Ochoa

Chen

Williams

WriteIn Marketing

Directory

25Figure 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

TrainingMapsPolicies

Personnel Discipline

Group Everyone Gets Read

ReadRead Read

ReadNo Inheritance

26Figure 1b-8: Assigning Directory Permissions in Windows Server 2003

1.SelectedDirectory

3. User or Group(Power Users)

4. PowerUser

Permissions

5.

2. 6.

27Figure 1b-9: File Service for Data Files

Save

Retrieve

User A User B User C

No Access

File Server with Programand Data Files

28Figure 1b-10: File Server Program Access

1.ProgramStored onFile Server File

Server

2.Program

Downloadedto Client PCWhen Called

3.ProgramExecuted

onClient PC

Client PC

29Figure 1b-11: File Server Program Access and Program Installation

2. Programdownloaded to

Client PCswhen called

1. Programis installedonly once,on a fileserver

FileServer

Client PC

Client PC

3. No needto installon eachclient PC

3. No needto installon eachclient PC

4.This process greatly reduces

software installation andupgrading costs

30Figure 1b-12: Print Server Operation

Hub orSwitch

Client PC

UTP up to100 m Print

Server Printer

Parallel or USB Cable1-2 meters

Print server feeds print jobs to the printer

Print server connects to printer viaparallel 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

31Figure 1b-12: Print Server Operation, Continued

Hub orSwitch

Client PC

Network-CapablePrinter

(with built-inprint server)

UTP up to 100 m

UTP up to100 m Print

Server Printer

Parallel Cable1-2 meters

Some high-end printersare network-capable,with built-in print servers

Connect directly to the switch

32Figure 1b-12: Print Server Operation, Continued

Hub orSwitch

UTP upto 100 m

Client PC

Printer

File Server acting as Print Server

UTP up to100 m Print

Server Printer

1-2m

Parallel Cable1-2 meters

File servers can act as print servers;But file servers are rarely near users

33Figure 1b-13: Print Server (Photo)

RJ-45Port

Parallelor USB

Port

PowerSupply

Port

Parallel or USBCable to PrinterRJ-45 Cord

to Switch Port

34Topics 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

35Topics 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

36Topics Covered

File Servers Sharing data files

File server program access

Print Servers Between the switch and the printer