Microsoft Internet Information Services

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Internet Information Services

by Karen Spring

Docid: 00018212

Publication Date: 1905

Report Type: PRODUCT


Internet Information Services (IIS), formerly known as Internet
Information Server, is Microsoft’s Web server for use with the Windows NT
family. IIS contains a modular
architecture that enables the addition or removal of sectors for
customization purposes. IIS is based upon Windows Process Activation
Service, which allows for the use of other protocols besides HTTPS and
HTTP. Currently in version 10.0, this report focuses on the key features and functions of IIS
7 and above.

Report Contents:


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Previously known as Microsoft’s Internet Information Server, Internet
Information Services (IIS) is an extensible Web server from Microsoft that
is used with the Windows NT family. IIS supports HTTP, HTTPS, FTP, FTPS,
SMTP, and NNTP. IIS can be used for hosting anything on the Web.

Faulkner Reports
Microsoft Company

IIS offers functionality in several

  • Choice
  • Control
  • Reliability
  • Security

Name: Microsoft
One Microsoft Way
Redmond, WA 98052-7329
Phone: (425) 882-8080
Fax: (425) 706-7329
Type of Vendor: Operating System and Application Software
Founded: 1975
Service Areas: Global
Stock Symbol: MSFT (NASDAQ)

Internet Information Systems is built upon a request-processing
architecture that offers the following:

  • The Windows Process Activation Service (WAS), which allows sites to
    use other protocols besides HTTP and HTTPS. 
  • A customizable Web server engine that allows for the addition or
    removal of modules. 
  • A system of request processing based upon pipelines from IIS and

An administrative tool is tasked with querying, adding, or removing
modules from IIS. Modules may be removed if they are no longer usable on
the server or if they require replacement with another module. 

In earlier versions of IIS, most functionality was restricted to the
server. Beginning with IIS 7, administrators can control which modules they want on
the server and which features they want removed. 

IIS offers the following benefits:

  • Centralized Web farm management – Centrally deploy and manage the
    configuration and content across a Web server farm. 
  • Delegated remote management – Enables administration tasks to be delegated
    to site owners while basic configuration and management tasks are handled
    without admin intervention. 
  • Administrative tools – Various tools, including managed code and scripting
    APIs, simplify daily administrative tasks. 
  • Web infrastructure – Built-in HTTP-based load balancing and request
    handling and routing enables the implementation of scalable Web
  • Dynamic caching and compression – HTTP compression delivers better
    performance for static and dynamic Web content. 
  • Diagnostic tools – Enables quick diagnosis of server and application
    issues and simplifies troubleshooting. 
  • Server protection – Uses minimal Web server footprint and automatic
    application to improve Web server security. 
  • Access protection – URL authorization rules and request filtering protect
    against malicious requests and other threats. 

Table 1 depicts the components and modules that comprise IIS. 

Table 1. IIS 7 and Above Components and Modules
IIS 7.0
and Above

IIS 7.0 features several components that perform critical functions for
the application and Web server roles: 

Protocol Listeners. Protocol listeners receive protocol-specific
requests, send them to IIS for processing, and then return responses to
requestors. In the latest version of IIS, Hypertext Transfer Protocol
Stack (HTTP.sys) is the main protocol listener but the system supports SSL
as well. 

HTTP.sys. The HTTP.sys listens for HTTP requests from the
network, passes the requests onto IIS for processing, and then returns
processed responses to client browsers. It supports kernel-mode caching,
kernel-mode request queuing, request preprocessing, and security

World Wide Web Publishing Service. The WWW Service acts as a
listener adapter for the HTTP listener. WWW Service configures HTTP.sys,
updates HTTP.sys when configurations change, and notifies WAS when a
request enters the request queue. WWW Service also collects the counters
for Web sites. 

Windows Process Activation Service. WAS manages application pool
configuration and worker processes. 

Native Modules

The native modules for IIS are included with a full installation of the
product. They can be replaced with other, customizable modules as

HTTP Modules. These modules respond to information and inquiries
sent in client headers, to return HTTP errors, to redirect requests, and
more. The HTTP Modules are: custom error, HTTP redirection, protocol
support, request filtering, and WebDAV. 

Security Modules. Some modules handle tasks designed for
security in the request process. There are additional modules for
authentication schemes, URL authorization, and request filtering. The
security modules include anonymous authentication, basic authentication,
certificate mapping authentication, digest authentication, IIS certificate
mapping authentication, request filtering, URL authorization, Windows
authentication, and IP restriction. 

Content Modules. These modules process requests for static
files, return to the default page when a client doesn’t specify a resource
in a request, and lists a directory’s contents. The content modules
consist of: CGI, default document, directory listing, ISAPI, ISAPI filter,
server-side includes code, static file, and fast CGI. 

Compression Modules. The dynamic compression and static
compression modules handle any compression tasks. 

Caching Modules. Caching improves performance of your
Web sites and Web applications by storing processed information, such as
Web pages, in memory on the server, and then reusing that information in
subsequent requests for the same resource. The caching modules consist of file cache,
HTTP cache, token cache, and URL cache. 

Logging and Diagnostics Modules. The logging modules support
loading of custom modules and passing information to HTTP.sys. The
diagnostics modules follow and report events during request processing and
include custom logging, failed request tracing, HTTP logging, request
monitor, and tracing.

Managed Support Modules. Consists of the managed engine and
configuration validation modules. 

Managed Modules In addition to the native modules, IIS offers managed modules to
provide enhanced functions. Some of these managed modules (i.e. URL
authorization) have a native module counterpart that provides a native
alternative to the managed module. The managed modules are only offered
with a full installation of IIS 7 and above. The managed modules are: anonymous
identification, default authentication, file authorization, forms
authentication, output cache, profile, role manager, session, URL
authorization, URL mappings module, and Windows authentication. 

IIS 10.0 Version 1709

IIS 10.0 Version 1709 is the latest version, which shipped with Windows 10
Fall Creators Update and Windows Server 2016 Version 1709. This version was
announced in October 2017. Features include: 

  • HTTP Strict Transport Security – This feature lets a Web site
    declare itself as a secure host and to inform browsers that it should only
    be contacted through HTTPS connections. 
  • Container enhancements – The IIS worker process can now be run
    directly. Changes have also been made to the Central Certificate Provider to
    run in containers. 
  • IIS Administration PowerShell Cmdlets – Improvements have been made
    as well as the roll out of three additional cmdlets. 
  • Logging enhancements – Microsoft introduced new server variables
    for the Cryptographic Protocol, the Cipher algorithm, the Key Exchange
    Algorithm, and the Message Authentication Algorithm. 

IIS Version 10.0

IIS 10.0 was rolled out in November 2016 and ships with Windows 10 and Windows
Server 2016. The notable features in IIS 10.0 are:

  • IIS on Nano Server – IIS is now available as a role on Nano
    Server. IIS for Nano supports both online (i.e. when the machine is
    running) and offline (i.e. when the machine is not running) installs.
    Nano Server is a remotely administered server operating system for
    private clouds and data centers and only supports 64-bit applications,
    tools, and agents. It is similar to Windows Server, but is
  • IIS in Containers – Support has been added for containers
    which are isolated, resource controlled, and portable operating
  • Microsoft IIS Administration – This REST API allows for the
    configuration and monitoring of the IIS instance. It is an open source
    project currently in development on GitHub. 
  • Wildcard Host Header Support – Wildcard Host Headers enable
    administrators to set up a Web server for a domain so that the Web
    server can provide requests for any subdomain. 
  • IISAdministration PowerShell Cmdlets – This feature
    includes a PowerShell module for managing IIS along with access to the
    ServerManager object.
  • HTTP/2 on IIS – With HTTP/2, a major upgrade to HTTP/1, which
    allows for a persistent connection to be used to service multiple
    simultaneous requests. IIS supports HTTP/2 over TLS.
  • CPU Optimization for NUMA Hardware – Includes improved
    performance on NUMA hardware through the IIS thread pool ideal CPU


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Microsoft IIS is a Web platform that is designed for developers who are looking
to create a Web site or a business that
hosts or develops Web sites or Windows Communication Foundation (WCF) services. Companies in various industries
including software engineering, IT, education, retail, and hosting/application
service providers have utilized IIS to address expanding infrastructure
requirements and improve performance.


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Table 2 lists the Windows Server 2016
operating requirements. IIS comes
bundled with Windows Server.

Table 2. Windows
Server 2016 Requirements
Support Description
  • 1.4 GHz (x64
    processor) minimum
  • 512 MB minimum
Disk Space
  • 32 GB minimum


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Support is available through the Microsoft Server Support Center which offers
contracts for businesses for all vendor products. Without a contract, companies
can opt for a la carte services that begin at $99 for email support.

In addition, IIS’ Web site consists of various self-help options in the
form of blogs, forums, community tools and tips, and the IIS Learning
Center. Users of IIS are free to browse the topics and pose questions
to Microsoft support engineers. 


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IIS is licensed as part of Windows NT, and as such, cannot be priced as an
individual component. IIS 10 is included with Windows 10 and Windows Server

Competing Products

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IIS’s top competition comes from Apache’s
Web Server and Nginx.

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About the

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Karen M. Spring is a staff editor for Faulkner Information
Services, tracking high-tech industries, including network security, data
breaches and cybercriminal activity, CRM, network management, Internet security,
and software tools. She writes regularly on high-tech topics for publications in
the k-12 and higher education industry. Previously, Ms. Spring was a marketing
specialist for two computer distributors, working closely with such clients as
3Com, IBM, Okidata, Unisys, and Acer.

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