Web Server Administration

1. Web Server Administration Chapter 5 Managing a Server

2. Overview • Understand the Web server administrator's view of server management • Examine networking models • Learn how users are authenticated • Manage users and groups

3. Overview • Manage file system permissions • Share resources in a network • Enforce network policies

4. Web Administrator's View of Server Management • Web server software is a product that works with the operating system • The server computer can run more than one software product such as e-mail and FTP • With both a LAN and the Web, controlling access is very important • The Web server can be part of the LAN • Web communication and LAN communication are different

5. Microsoft LAN Networking Models-Workgroup • Treats each computer in the network as an equal, or peer • Also called peer-to-peer networking • Each computer is a client and a server • When you allow others to access resources on your computer, your computer is acting as a server • When you access resources on another computer, your computer is acting as a client

6. Microsoft LAN Networking Models-Workgroup • Appropriate for networks with 10 or less computers • A number of disadvantages • Most users do not want to administer resources on their computer • Need user names and passwords of users who need resources • Difficult to keep track of changing passwords

7. Microsoft LAN Networking Models-Domain • One or more servers centralize control • Computers are part of a domain • Single, centralized logon • Single point of control • Users can be given access to resources anywhere in the domain

8. Client/Server Networking Model • Client represents a program such as a browser or an e-mail client • Server has a corresponding program that communicates with the client • Server program known as a service in Windows or a daemon in Linux • Networking in Linux follows the client/server model • Telnet is used to log on to another computer

9. Authenticating Users • Process of determining a user's true identity • Three basic methods • What you know – user name and passwords • What you have – entry card • Who you are – biometrics

10. Implementing an Authentication System • If a Windows network has older computers running NT, 95, or 98, the server must use NTLM • It is not as secure as Kerberos, which is the default for Windows 2000, 2003, and XP

11. Managing Users and Groups • Users need accounts to access resources on a server • On a Web server there is a restricted account that is used on behalf of Internet users • In a LAN, users with common resource needs are put in a group, and the group is given access to the resource

12. Managing Users and Groups in Windows • Windows has an account called system • It represents the operating system and it has many of the same privileges of the administrator • Often needed by server programs • Linux typically uses unique accounts for each daemon

13. Users and Groups in Windows • Local accounts exist on a single computer and can be used to control resources only on that computer • Domain accounts can be used to control resources on all the computers that are part of the domain • Active Directory (AD) allows domains to be grouped into a forest • Microsoft Exchange requires AD

14. Groups in Windows • Domain local groups have members from the same domain • Assign permissions to resources in the same domain • Global groups have members from the same domain • Can be used to assign permissions to resources in any domain • Universal groups can have members from any domain • Can be used to assign permissions to resources in any domain

15. Users and Groups in Linux • Properties of user accounts

16. File System Permissions • Permissions allow you to control access to the resources on a computer such as a Web page, a document, or a program • In Windows, the NTFS file system is required in order to assign permissions • All Linux file systems incorporate permissions

17. File System Permissions in Windows

18. File System Permissions in Linux

19. Linux Permissions • Permissions are set for user, group, and others • Each permission is set with a single digit from 0 to 7 based on the combination of permissions • read = 4 • write = 2 • execute = 1

20. Using chmod to Set Permissions

21. Sharing Resources in a Windows Network • Shared folders require permissions • When comparing share permissions and NTFS permissions, the most restrictive permission takes precedence

22. Enforcing Network Policies • You can control a number of policies in both Windows and Linux • Windows has many more policies but the majority are appropriate for LANs • A common policy involves passwords • Number of days before change allowed • Number of days before change required

23. Summary • The Web server has a guest user account that is used to access Web pages • Windows LAN models include the workgroup and domain models • Linux only uses the client/server model • Authentication is based on what you know, what you have, and who you are • Core of security incorporates users, groups, and permissions