Resource Sharing Over a Network

1
Resource Sharing Over a Network

• Guide to Operating Systems
• Third Edition

2
Objectives

• After reading this chapter and completing the
  exercises you will be able to
• Explain the principles behind sharing disks and
  files on a network
• Set up accounts, groups, security, and disk and
  file sharing on network server operating systems

3
Objectives (continued)

• After reading this chapter and completing the
  exercises you will be able to
• Set up disk and file sharing on client operating
  systems
• Set up printer sharing on server and client
  operating systems
• Discuss how network and Internet servers are used
  for vast information-sharing networks

4
Sharing Disks, Files and Printers

• One of the first reasons for linking a
  workstations operating system onto a network
• NetWare was early on the scene to enable file
  sharing through a server
• by downloading a file from a file server
• by purchasing third-party software to create a
  special shared drive

5
Sharing Disks, Files and Printers (continued)

• Share entire applications over the network
• Download the entire executable
• Only one version needed on the server
• Mapping
• enables a client workstation to attach to the
  shared drive of another workstation or server
• drive letter assigned

6
Sharing Disks, Files and Printers (continued)

• Mounted volume
• term used in UNIX/Linux and Mac OS X for a mapped
  drive

7
Securing Shared Resources

• Potential security risk for non-authorized users
  to access a file or use a printer
• Operating systems discussed in this book offer
  security measures

8
Sharing Disks and Files Through Server Network
Operating Systems

• Examples of server network operating systems that
  share disks and files over a network
• Windows 2000 Server
• Windows Server 2003
• UNIX/Linux
• Mac OS X Server
• NetWare

9
Sharing Disks and Files Through Server Network
Operating Systems

• Network administrator may establish security
• by assigning accounts, account passwords, groups,
  and access privileges

10
Windows 2000 Server and Windows Server 2003

• Uses accounts, groups, and permissions
• Steps involved include setting up the following
• Groups Account policies
• User accounts Permissions
• Shared disk and folders

11
Windows 2000 Server and Windows Server 2003
(continued)

• Use groups to manage resources and permissions
• Local
• Domain local
• Global
• Universal

12
Windows 2000 Server and Windows Server 2003
(continued)

• Groups are defined as security or distribution
  groups
• Security groups
• used to enable access to resources on a
  standalone server or in Active Directory
• Distribution groups
• used for e-mail or telephone

13
Windows 2000 Server and Windows Server 2003
(continued)

• Container object
• entity that is used to group together resources
  in a directory service
• Tree
• consists of one or more domains
• Forest
• houses one or more trees

14
Windows 2000 Server and Windows Server 2003
(continued)

• Universal group guidelines
• use global groups to hold user accounts as
  members
• use domain local groups to provide access to
  resources in a specific domain
• use universal groups to provide extensive access
  to resources
• manage user accounts access

15
Windows NT Server

• Trusted domain
• such as college.edu
• granted access to the resources in another domain
  such as research.college.edu
• Trusting domain
• research.college.edu allows access to its
  resources to college.edu

16
Windows 2000 Server and Windows Server 2003
(continued)

• Before any accounts are created, it is wise to
  establish the account policies
• Three categories
• Password security
• Account Lockout
• Kerberos security

17
Windows 2000 Server and Windows Server 2003
(continued)

• Password security options
• enforce password history
• maximum password age
• minimum password age
• minimum password length
• password complexity requirements
• password storage using reversible encryption

18
Windows 2000 Server and Windows Server 2003
(continued)

• Account lockout options
• account lockout duration
• account lockout threshold
• reset account lockout count

19
Windows 2000 Server and Windows Server 2003
(continued)

• Kerberos options
• enforce user logon restrictions
• maximum lifetime for a service ticket
• maximum lifetime for a user ticket
• maximum lifetime for a user ticket renewal
• maximum tolerance for a computer clock
  synchronization

20
Windows 2000 Server and Windows Server 2003
(continued)

• Share
• an object given a name and made visible to
  network users
• Disk or folder - shared through its properties

21
Windows 2000 Server and Windows Server 2003
(continued)

• Share permissions
• Read
• Change
• Full Control

22
Windows 2000 Server and Windows Server 2003
(continued)

• Dialog box in Figure 9-6 has a caching button
• Caching
• enables you to set up a folder so that it can be
  accessed by a client, even when the client is not
  connected to the network
• Web sharing
• files available on a Web server for HTML or FTP
  access
• See Tables 9-2 and 9-3

23
Windows 2000 Server and Windows Server 2003
(continued)
24
Windows 2000 Server and Windows Server 2003
(continued)
25
Windows 2000 Server and Windows Server 2003
(continued)

• Troubleshooting a security conflict
• review folder and share permissions
• take into account what happens when a folder or
  files are copied or moved
• inherited properties

26
UNIX and Linux

• User identification number (UID)
• each user account in UNIX is associated with a
  UID
• Group identification number (GID)
• users who have common access needs

27
UNIX and Linux (continued)

• The password file (/etc/passwd) contains
• user name
• encrypted password or a reference to the shadow
  file
• UID
• GID
• information about the user
• location of the users home directory
• which shell to use

28
UNIX and Linux (continued)

• Shadow file (/etc/shadow) contains password
  restriction information
• minimum and the maximum number of days between
  password changes
• Information on when last changed
• Warning information about password expiration
• Amount of time that the account can be inactive
  before access is prohibited

29
UNIX and Linux (continued)

• Home directories
• areas on the server in which users store data
• Information about groups is typically stored in
  the /etc/group file

30
UNIX and Linux (continued)

• Permissions are granted on the basis of
• ownership
• group membership
• other (or World)
• all (all is not used in every version of UNIX,
  but is included in Red Hat Enterprise Linux)
• Permissions are set up by using the chmod command
• Chmod has two different formats, symbolic and
  octal

31
NetWare

• Novell NetWare server installation
• first task is to design a file structure
• Default directories
• SYSTEM
• PUBLIC
• LOGIN
• HOME
• APPS
• DATA

32
NetWare (continued)

• Net Administrator tasks
• Set security on each directory, subdirectory, and
  on particular files
• Create an account and account password for each
  user
• Set up groups as a way to provide shortcuts for
  managing security

33
NetWare (continued)

• Search drive
• given drive letters such as S1 for the first
  drive, S2 for the second drive, and so on
• Difference between a mapped network drive and a
  mapped search drive
• NetWare can execute a file on a search drive,
  whether the file is in the main directory or in a
  subdirectory under the search drive

34
NetWare (continued)

• A login script is a file of commands associated
  with an account or a group of accounts

35
NetWare (continued)

• A user account can be set up in ConsoleOne using
  several kinds of restrictions
• Requiring a password
• Setting a minimum password length
• Requiring that a password is changed within a
  specified interval of time
• The remainder are listed on page 453 of the
  textbook

36
NetWare (continued)

• Administrator can grant rights to access specific
  directories, subdirectories, and files
• The rights control the ability to
• Perform a directory listing
• Create a new directory, subdirectory, or file
• Read contents of a directory, subdirectory, or
  file
• Write to the contents of a file
• Refer to the list on page 454 of the textbook for
  the rest

37
NetWare (continued)

• Objects
• such as user accounts, groups, printers,
  directories, subdirectories, files, and other
  resources
• Novell Directory Services (NDS)
• stores information about objects
• Leaf objects
• store information about clients

38
Mac OS X Server

• The Mac OS X Server is designed as a true server
• file sharing
• printer sharing
• managing network users and groups
• providing Web services
• Mac OS X Server
• can support up to several thousand users
• includes the Apache Web server software
• supports TCP/IP and AppleTalk

39
Mac OS X Server (continued)

• Included tools
• Server Admin
• Macintosh Manager
• Share points
• shared resources on a server

40
Mac OS X Server (continued)

• Logging of events can include
• Login and Logout events
• Opened files
• Newly created files
• Newly created folders
• Deleted files and folders

41
Accessing and Sharing Disks and Files Through
Client Network Operating Systems

• Many operating systems
• include the ability to act as clients
• to map to disks and directories on servers

42
Accessing and Sharing Resources in Windows 2000
Professional

• Windows 2000 Professional
• Access a shared drive over the network
• Map the drive using My Network Places
• The steps for mapping a drive are shown on page
  457
• Same process for Windows 2000 Server

43
Accessing and Sharing Resources in Windows XP

• Uses My Network Places to locate and map network
  drives
• Fastest way to access My Network Places is to use
  the steps on page 458

44
Accessing and Sharing Resources in Windows XP
(continued)
45
Accessing Shared Resources via UNIX/Linux and
Specialized Utilities

• Network File System (NFS)
• provides file transfer capabilities
• NFS in Red Hat Enterprise Linux 3.0
• enable portmap
• enable rpc.mountd
• enable rpc.nfsd

46
Accessing Shared Resources via UNIX/Linux and
Specialized Utilities (continued)

• UNIX/Linux can access share Windows
  2000/XP/Server 2003 with Samba

47
Accessing and Sharing Resources via Mac OS X

• In Mac OS X, you connect to another computer that
  is sharing a disk or folder by using the Go menu
• To mount a shared drive
• open the Go menu
• select Connect To
• Server
• enter address of
• server

48
Accessing and Sharing Resources via Mac OS X
(continued)

• Establish the network identity and turn on file
  sharing through System Preferences
• Privileges are set in order to enable access

49
Sharing Printing Devices

• Operating systems discussed in this book have the
  ability to share printers as well as disks,
  directories, and files

50
Windows-based Systems

• Configure printing by using the Add Printer
  Wizard
• Once a printer is set up, it appears in the
  Printers folder
• In Windows XP and Windows Server 2003, click
  Start, and click Printers and Faxes
• Right-click the printer to access menu options

51
Windows-based Systems (continued)

• Windows 2000/XP/Server 2003 share permissions
• Print
• Manage Documents
• Manage Printers
• Special permissions

52
UNIX/Linux

• UNIX printing
• log on to the UNIX server and printing to one of
  its printers
• set up to use the BSD or the SVR4 spooling system
  as describe in Chapter 5
• Red Hat Enterprise Linux 3.0
• GNOME Print Manager tool

53
NetWare

• Shared printing
• queue-based printing
• Novell Distributed Print Services (NDPS)

54
Mac OS X

• Methods of printer sharing
• can make a connected local printer available to
  other computers running the Mac OS on a network
• can attach to a shared printer offered by another
  workstation on the network

55
Network and Internet Resource Servers

• Resource Servers
• NetWare
• UNIX/Linux
• Windows 2000/Server 2003
• Mac OS X servers

56
Network and Internet Resource Servers

• Functions
• e-mail
• e-commerce
• video-conferencing
• multimedia
• client/server applications
• web servers

57
Summary

• Resource sharing is why networks exist and are
  thriving
• Security is important for network resources
• Groups, user accounts, and permissions permit or
  restrict access as determined by the administrator

58
Summary (continued)

• Client operating systems have utilities to enable
  access or share resources over the network
• Network server operating systems continue to
  provide more and more ways to share resources