Hardware and software requirements are based on the information gathered and the requirements set forth in the design and planning stages. The necessary hardware and software requirements should match the goals and objectives of the project. These details are very specific and describe all the resources needed for hardware and software. For example, four IIS servers will each require dual processors, 1GB RAM, triple-channel RAID controllers, and 15K rpm disk drives.

Fault tolerance is a key aspect of any Web infrastructure and should be addressed during the planning and designing phases. Although some Web sites can afford to have downtime, others may require 99.999% uptime. Service Level Agreements (SLAs) should be determined from the operational goals. When an SLA is in place, such as a minimum of two hours of downtime at any one time, the appropriate fault tolerance can be applied to the Web infrastructure.

Various technologies can be applied to a Windows Server 2003 Web infrastructure to support even the most demanding SLAs. For example, Windows Server 2003 Web servers can use network load balancing (NLB) to distribute the load among multiple Web servers and also provide fault tolerance. NLB is more suited and less costly than using Microsoft Cluster Service to provide fault tolerance. Another way to promote fault tolerance is to tier the environment so that various services are segmented (for example, IIS tier, application tier, database tier, messaging tier), as shown in Figure 11.1.

Figure 11.1. Fault tolerance using a tier environment.

As a previous version of Windows is upgraded to Windows Server 2003, IIS is also automatically upgraded. During Windows Server 2003 setup, all IIS-related services running on the previous Windows version are disabled during the upgrade. These services and more are enabled after the upgrade is complete.

Windows Server 2003’s IIS is inherently more secure than any other versions. As a result, all Web sites currently upgraded to IIS 6 are stopped after the upgrade. The primary reason for stopping all Web sites is to help prevent IIS security vulnerabilities because of previous Windows defaults. Therefore, if a previous Windows server has IIS installed but isn’t supposed to be serving as a Web server, the servers will be more secure than before by default. In this scenario, Web sites aren’t enabled.

Another key point to upgrading from previous versions of IIS is that all applications are configured in the IIS 5 isolation mode. This configuration preserves the applications and provides compatibility.

There are many Web services components that need to be configured to optimize IIS for security, functionality, and redundancy. The IIS snap-in, shown in Figure 11.3, is the interface in which you administer the IIS services. In the left pane of the snap-in, you can find the following folders:

Figure 11.3. IIS services administration window.

Figure 11.4. Web Service Extensions window.

As mentioned earlier, IIS can support up to 10,000 Web sites on a single Web server. The number of Web sites that you have depends on the way the system is configured, including the number of processors, the amount of RAM, bandwidth, and more. For every Web site that the system supports for the Internet, there must be a public IP address and registered domain name. However, if you have only one public IP address and you want to support other Web sites, you can also create virtual directories to have those sites serving users on the Internet.

Using virtual directories is a sound option to support more than one Web site on a single IP address, but keep in mind that users from the Internet will use a subdirectory from your Web site to reach a separate Web site. For instance, a company hosting http://www.companyabc.com decides to host another Web site using a virtual directory; in this case, users would connect to http://www.companyabc.com/NewWebSite/ to be able to connect to the second Web site.

The Default Web Site is located within the Web Sites folder in the IIS snap-in. You can use the default Web site for your own Web site, but it is best that you create and configure a separate Web site.

To begin creating a new Web site, do the following:

Right-clicking Web Sites or the Default Web Site in the snap-in and then selecting Properties gives you options for globally modifying the default settings for a Web site. However, right-clicking a specific Web site gives more options for configuring only that Web site. For simplicity, this section will describe the default Web site settings.

The Default Web Site Properties page, shown in Figure 11.5, has some of the tabs for configuring a Web site. From here, you can control everything from identification to specific filtering. These options are as follows:

Figure 11.5. Default Web Site Properties page.

Figure 11.6. Performance tab bandwidth configuration options.

Figure 11.7. Web site home directory and application configuration options.

Figure 11.8. Directory Security tab.

One other tab, called Service, appears only after you right-click the Web Sites folder and select Properties. On this tab, you can set IIS isolation mode to run as an IIS 5 isolation mode server. Also, you can set HTTP compression on application files as well as static files to save bandwidth. This tab is shown in Figure 11.9.

Figure 11.9. HTTP compression settings.

Virtual directories extend the home directory of your Web site by providing an alias linking another directory not contained within the home directory. This alias will appear to users as simply a subfolder to the Web site even though it may be located on an entirely different server.

The virtual directory can contain documents and other information for the Web site as well as a new Web site. For example, if CompanyABC’s Web site (http://www.companyabc.com) wants to host a temporary Web site for another organization, it could use a virtual directory to contain the Web site. In this scenario, CompanyXYZ would have its own Web site located at http://www.companyabc.com/companyxyz/.

To create a virtual directory using the IIS Manager, do the following:

Similar to Web site properties, a virtual directory has properties pages that allow you to set specific options. Figure 11.10 illustrates the virtual directory properties pages. You’ll notice that there is a smaller subset of configuration options for a virtual directory in comparison to a Web site.

Figure 11.10. Virtual directory properties page.

There are five configuration tabs including Virtual Directory, Documents, Directory Security, HTTP Headers, and Custom Errors. The tabs represent and are applied to the virtual directory but are similar to the configuration tabs for the Web site.

IIS supports two modes of application isolation: worker process isolation mode and IIS 5 isolation mode. Both modes of operation use Http.sys and application pooling. Application pools are queues for requests within Http.sys and one or more worker processes. Applications are assigned to an application pool based on their URL, and many pools can run at the same time. For example, by default, DefaultAppPool is located within the Application Pools folder.

On a given Web site there may be only one mode of operation working to support the Web applications. It is recommended to use worker process isolation mode exclusively unless there is a specific compatibility issue with a particular application. Using worker process mode gives the greatest boost to reliability and availability. Another reason to use worker process isolation mode is that the type of application isolation that is in use causes IIS to dynamically adjust internal architecture parameters to accommodate the fundamental differences between the two isolation modes.

The IIS 5 isolation mode is used primarily to support applications that may depend on features in earlier versions (mainly IIS 5) of IIS. It’s important to use this isolation mode only when the application cannot work properly under the worker process isolation mode. Otherwise, this mode can increase the resource requirements needed to run such applications when compared to worker process mode. This could, in turn, affect performance and reliability of the system.

Generally speaking, Web sites are expected to be up and running without little interruption. Moreover, these Web sites must adequately service user requests. Sites that require this level of service must incorporate fault tolerance into the infrastructure’s design. For example, many Web servers must be linked together by some form of network load balancing to ensure minimal downtime.

Even the most reliable Web sites must have the servers refreshed at some point so that the applications can be recycled or other maintenance can occur. Another solution that can work in conjunction with infrastructure fault tolerance is using IIS 6 process recycling. Using IIS 6 minimizes the number of server refreshes that may be required because of its capability to automatically refresh Web applications without affecting the rest of the system or stopping service to that Web application. Process recycling is also extremely useful for those Web applications that can be problematic because the server must be restarted. Often it is difficult to rewrite an application to work better because of budgetary reasons, technical limitations, or extensive effort required to make the changes.

Within the Properties Recycling tab of an application pool such as the one shown in Figure 11.11, applications can be recycled every so many minutes (the default is 1,740 minutes or 29 hours), after a set number of requests to that application, at a specified time, or when a certain amount of physical or virtual memory is used.

Figure 11.11. Application recycling configurations.

When one of these events occurs, one of two procedures can happen:

Process recycling is a welcomed feature; however, it doesn’t apply to every situation. For obvious reasons, process recycling doesn’t work on static content, but it also doesn’t work if the Web site uses custom-built ISAPI applications. Also, if session state data is required on the Web site, it’s important to be aware that session state data may be lost during process recycling.

Using IIS to monitor applications is now feasible with IIS 6. More specifically, WAS can perform the following health-monitoring procedures:

When a worker process doesn’t respond to a ping, WAS can terminate the worker process and create another one so that the application can keep servicing requests.

There are many variables with how applications perform. They include, but aren’t limited to, the server resources, the way the application is written, and the way the environment is structured.

Process recycling and health detection help ensure that applications are running efficiently and effectively. Another set of features is located under the Performance tab of the application pool properties page. Within the Performance tab are options specifically geared toward optimizing performance, including the following:

Numerous application types are supported on IIS, including, but not limited to, Active Server Pages, ASP.NET, COM+, Java, Common Gateway Interface (CGI), and FastCGI. No matter what types of applications the server will host, it’s imperative to adequately test them. You should test the applications under various workloads and consider using those that are specifically designed to run on the IIS platform. For instance, ASP and ASP.NET were developed solely for IIS and can therefore perform much better than other technologies that weren’t built for a specific platform.

IIS now can isolate FTP users so that FTP content is protected. This is an especially useful feature for ISPs and ASPs servicing a large number of users. Each FTP user can have his own separate directory in which to upload and download files to the Web or FTP server. As users connect, they see only their directory as the top-level directory and can’t browse other FTP directories. Permissions can be set on the FTP home directory to allow create, modify, or delete operations.

FTP user isolation is based on an FTP site rather than at the server level and is either enabled or disabled. However, sites that need to enable FTP user isolation aren’t forced to strictly use this feature. You can enable anonymous access in conjunction with FTP user isolation by creating a virtual directory within the FTP site and allowing read-only access. The only limitation to mixing the FTP user isolation and anonymous access is that information can be downloaded only from the public or read-only virtual directory.

By default, the Default FTP Site is created and enabled. However, to create a new FTP site (in addition to the Default FTP Site), do the following:

As you can see in Figure 11.13 and Figure 11.14, you can access two separate properties pages for FTP. The first properties page appears after you right-click the FTP Sites folder. The second properties page is for a specific FTP site.

Figure 11.13. FTP Sites Properties page.

Figure 11.14. FTP configuration settings.

The FTP Sites folder properties page is used to configure global properties for FTP sites. If multiple FTP sites are created, these settings will be the default configurations for the sites.

Within the FTP Sites folder properties are the following configuration tabs:

Figure 11.15. Security Accounts configuration tab.

The differences between the FTP Sites folder properties and a specific Web site are minimal. The following tabs in the FTP site properties are different:

The Simple Mail Transport Protocol Service is a messaging service that allows email messages to be sent from the Web server. In essence, the IIS Web server can also be an email server. To install the SMTP Service, do the following:

IIS can host internal or external newsgroups through the use of the NNTP Service. Newsgroups are still a popular way to extend communications to a large audience. The newsgroups can be used for a variety of tasks, including sharing information and data.

The News Service provides newsgroups using the Network News Transport Protocol, which is the protocol responsible for managing the messages for each newsgroup. It’s unlike mass emailing, though, because the messages are exchanged either server-to-server or client-to-server, never server-to-client. In the first scenario (server-to-server), messages can be exchanged between two NNTP servers. A common example is an internal NNTP server requesting messages from an external server from an ISP. Clients can subscribe (and unsubscribe) to newsgroups to read and post messages.

An NNTP server requires additional disk and network capacity due to the high disk space utilization and potentially high bandwidth requirements. To install a news server, you can follow the same procedures as you did installing the SMTP server, except you need to select the NNTP Service rather than the SMTP Service.

Indexing is a Windows Server 2003 component that has been separated from IIS. If this service is installed on the Web server, all content can be indexed to provide faster search results of Web-based information.

Windows Server 2003 security actually begins during the planning and designing phases so that every conceivable security aspect is addressed. This can entail physical, logical (Windows Server 2003, applications, and so on), and communications security.

When you’re securing the Windows Server 2003 Web server, it’s important to use NTFS on the disk subsystem and apply the latest service pack and security patches. Using NTFS is critical because it can have appropriate permissions set on files, folders, and shares. Also, keeping up to date with service packs and patches ensures that Windows Server 2003 is operating with the greatest amount of protection.

Application security on the Windows Server 2003 Web server should be carefully reviewed, especially if it’s a custom-built application. If the application is developed by a vendor, make sure that you have an application that is certified to run on Windows Server 2003 and that the latest service packs and patches have been applied and tested.

As mentioned earlier, IIS can display only static content (.htm, image files, and so on) by default until you manually enable dynamic content. IIS gives granular control over the dynamic content. For example, you can enable Active Server Pages but disable ASP.NET applications.

To enable or disable dynamic information, do the following:

Using the Web Service Extensions interface, you can also add and allow extensions for specific applications that may not be already listed.

Authentication is a process that verifies that users are who they say they are. IIS supports a multitude of authentication methods, including the following:

These authentication methods can be enabled under the Authentication Methods dialog box, as illustrated in Figure 11.17. You can view this window by clicking the Edit button located on the Directory Security tab of a Web site properties page.

Figure 11.17. Authentication Methods settings.

Windows Server 2003 auditing can be applied to Web and FTP sites to document attempts to log on (successful and unsuccessful), to gain unauthorized access to service accounts, to modify or delete files, and to execute restricted commands. These events can be viewed through the Event Viewer. It’s also important to monitor IIS logs in conjunction with audited events to determine how, when, and if external users were trying to gain unauthorized access.

Secure Sockets Layer preserves user and content integrity as well as confidentiality so that communications from a client and the Web server, containing sensitive data such as passwords or credit card information, are protected. SSL is based on the public key security protocol that protects communication by encrypting data before being transmitted.

Previous versions of IIS could use SSL, and IIS 6 is no different. The exception to this, though, is how SSL is implemented within IIS. The version implemented within Windows Server 2003’s IIS has the following improvements:

SSL certificates serve three primary purposes, although they are typically used to encrypt connections. These purposes include the following:

From an IIS perspective, SSL can be applied to an entire Web site, directories, or specific files within the Web site. SSL configuration can be done through the IIS snap-in located on the Start, Administrative Tools menu.

To use SSL on a Web site, it must first be requested and then installed. The request can be created to obtain a certificate either from an external, trusted CA or from an internal PKI. To request a SSL certificate for a Web site, do the following:

After the certificate has been requested, it must be submitted to a trusted CA to process. To submit the newly created certificate request to an internal CA, do the following:

To apply the SSL certificate, do the following:

FTP is, by default, an unsecured protocol. It’s unsecured due to the method of user authentication and the transfer of the data. For example, if users need to supply a username and password, the information can be captured and easily read because the information is transmitted in clear text.

Many organizations have abandoned using FTP for supplying read-only downloads to external users. In this scenario, organizations are using HTTP instead to provide downloads. Securing HTTP is much simpler than FTP and doesn’t require as much administration.

IIS logging should be viewed as a necessity rather than an optional feature of IIS. Logging helps to ensure IIS security and is also a great maintenance and troubleshooting function. Reviewing logs gives you intimate details of what is going on in the system. This information can then be used to review maintenance procedures and identify problems in the system.

IIS text-based logging, such as the W3C Extended Log File Format, Microsoft IIS Log File Format, and NCSA Common Log File Format, is controlled by Http.sys, a kernelmode process. This is a change from previous versions in which logging was a user-mode process. The other log file format, ODBC, is implemented using a user-mode worker process.