IIS Interview Questions and Answers [ TOP & MOST ASKED ]

1. What is IIS in ASP.NET?

Ans:

IIS is an acronym that stands for an Internet Information Server. It is one of the most famous web servers developed by a Microsoft and is used to host and offer an Internet-based services to ASP.NET and ASP web applications.

2. What are the major important features of an Internet Information Server?

Ans:

• IIS or Internet Information Server consists of a programs for that building and administering web applications and also search engines.
• It encourages writing web-based applications that access a databases such as SQL Server.
• It also facilitates developers to made their computers work as a web server and provides the functionality to develop and deploy an ASP.NET web applications on the server.
• IIS offers a redesigned WWW architecture that facilitates users to achieve a better performance, reliability, scalability, and security for websites.
• IIS can improve the availability of websites and applications for an organization by lowering the system administration and the cost of deployment.

3. What are the process for hosting a website for IIS?

Ans:

• By using a folder for web sharing.
• By generating a virtual directory.

4. What are the key functionalities of IIS?

Ans:

The Visual studio application consists of its own ASP.NET engine that can simply run ASP.NET web applications. have to click on the Run button to start an application. But, this is only in the case of a local environment. If host it on the webserver from where all users can accessed the sites, then require the IIS.

5. Which are the most protocols that IIS supports?

Ans:

The major protocols are that IIS supports are HTTP, HTTPS, FTP, FTPS, SMTP, NNTP, etc.

6. What do understand by Kernel Mode and User Mode in IIS?

Ans:

The Kernel Mode and an User Mode are the 2 major layers of IIS architecture.

7. What are the newest features added in IIS 8.5?

Ans:

The 2 newest features added in the IIS 8.5 are enhanced for logging capabilities and also dynamic site activation.

8. What do understand by virtual directory in IIS?

Ans:

In IIS, the virtual directory is the name of a directory that is mapped to the physical directory inthe local server.

9. What are the various IIS versions available in various operating systems?

Ans:

IIS is the most used in HTTP server in the world that runs on a Windows. Following is a list of various IIS versions available in various Windows operating systems:

• Windows Server 2008, Windows Vista: Home Premium/ Ultimate run IIS 7.0
• Windows Server 2003 runs IIS 6.0
• Windows XP Professional runs IIS 5.1

10. What is the use of an Application Pool in an IIS?

Ans:

The major purpose behind an using the Application Pool in IIS is to separate applications from each other and simplify a management. The Application Pool explains a group of settings for the worker processes that keep request processing for all of the applications in a pool.

11. What are the two major components of SVCHost.exe?

Ans:

The two major components of SVCHost.exe are WWW Publishing Service (W3SVC) and Windows Activation Process (WAP).

12. What is the web farm in IIS? And What are its advantages?

Ans:

• In IIS, a web farm is a process of hosting a web applications on multiple web servers using the load balancer. It is a group of two or more web servers/nodes that host a multiple instances of an app. It offers a load balancer method to avoid the high load on a single server and distributes the traffic to a various server on the same web application. When a user sends a request to a web farm, the load balancer distributes a requests to the web farm’s nodes to prevent a high load on a single server.
• Availability & Reliability: A web farm is a group of two or more nodes that host a multiple instances of an app. When one or more nodes fail, the load balancer can route the users’ requests to an other functioning nodes to continue the request processing. This is how it provides high availability and reliability.
• Better performance than a single server can provide is provided by a web farm’s cluster of servers.
• Scalability: It can increase or decrease the number of active nodes according to their workload required capacity. There are several web farm platform technologies, like Azure App Service, that can automatically add or remove nodes at the system administrator’s request or automatically without a human intervention.
• Maintainability: It made the system management simple as a web farm’s nodes can rely on shared services. For example, the nodes of a web farm can rely upon a one database server and a generall network location for static resources.

13. What steps are used to install and configure the IIS web farm?

Ans:

• First of all, have to install the IIS web farm infrastructure.
• After that, configure a IIS web farm servers.
• Have to configure a IIS web farm load balancing in the third step.
• After configuring a IIS web farm load balancing, must configure the SSL central certificate store.
• In the last step, configure an application deployment.

14. What do understand about a web garden in IIS?

Ans:

A web garden is a configuration in which an IIS application pool is set up to run within a multiple worker processes on a single server. An application pool can be configured for the multiple websites hosted in IIS. When implement a web garden, it split the website’s processing among several worker processes.

15. What are the advantages of using the web gardens in IIS?

Ans:

• A web garden provide applications that are not CPU-bound.
• It offers applications that made long-running database requests, like high computational database transactions.
• It offers more concurrent synchronization operations per CPU by increasing the Maximum Worker Process property value.
• It offers great application availability by sharing requests between multiple worker processes.
• It uses processor affinity, where an application can be swapped out according to their preferences and tag setting.
• It consumes a more less physical space while configuration.

16. What are the key differences between the web farm and a web garden?

Ans:

A web farm is a web hosting system which consists of multiple web servers for the multiple clients. This is majorly used to prevent a traffic and allow smooth availability of the resources to all the clients. So a web farm is used to while hosting a single web application on the multiple web servers to distribute a load among them. On the other hand, a web garden is the hosting web system where an application pool is configured while specifying the number of the worker processes.

17. What is the DefaultAppPool in IIS?

Ans:

DefaultAppPool is a folder made when we install the Internet Information Service on the computer. It is not a virus or malware. It is the name of the default application pool in the IIS. The Internet Information Service or IIS is the webserver software included with a Windows.

18. Is it safe to delete a IIS AppPool DefaultAppPool?

Ans:

When install the IIS service on a computer, it creates DefaultAppPool automatically. It is not malware or a virus, so don’t require to delete it. It is not safe to delete this folder because an IIS may not work properly when it doesn’t exist, should just leave it alone and do not use it, should also ensured that nothing is using it.

19. What is the application pool in the IIS?

Ans:

In IIS, an application pool denotes a group of one or more worker processes configured with general settings that serve requests to one or more applications assigned to that application pool. An application pool is majorly used to separate sets of IIS worker processes that share the same configuration and application boundaries. It is done to achieve better security, reliability, scalability, availability and performance and keep running without impacting each other. The worker process serves as the process boundary that separates every application pool. When one worker process or an application faces any problems or recycles, other applications or worker processes are not affected. A single application pool can have multiple worker processes.

20. What are the log files in IIS? / What do I understand by IIS logs?

Ans:

Log files or IIS logs record data from Internet Information Services, web pages, and apps. While IIS itself ensured the scalability and flexibility of the web resources, the log files are used to record various actions on a server and specific statistics about the websites,like the date, time, user data, site visits, IPs, queries, and volume of the transmitted data.

21. What are the additional or enhanced security features introduced in the IIS 7.5?

Ans:

• IP security
• URL authorization
• Client certificate mapping
• Request filtering etc.

22. What is the default identity of the application pool?

Ans:

The default identity of an application pool is a Network Services.

23. What are the various modules in the IIS 7.0 modular architecture?

Ans:

• Content module
• Compression module
• Caching module
• Security module
• Logging and diagnostic module etc.

24. What do you understand about the identities of an application pool?

Ans:

When run the site on own server or in the cloud, must ensured the security feature as a top priority list. IIS offers this security feature in the name of application pool identity. Application pool identity is the security feature of an IIS. Microsoft introduced this feature in the Service Pack 2 (SP2) of Windows Server 2008 and Windows Vista. An application pool identity the facilitates us to run an application pool under a unique account without having to generated and manage the domain or local accounts.

25. What are an ISAPI and ISAPI extensions in the IIS?

Ans:

ISAPI is an open and faster specification introduced by the Microsoft Inc. It is faster and high flexible than CGI for extending IIS. It is a powerful application as ASP pages are processed through the ISAPI extension called ASP.dll. ISAPI extensions are the applications that run on IIS and have access to all the functionality provided by IIS. Clients can access the ISAPI extensions similarly as they access a static HTML file or dynamic ASP file.

26. How can we enable ISAPI in IIS?

Ans:

• First, go Web Server (IIS) pane.
• After that, scroll the Role Services section and click a Add Role Services.
• After going to the “Select Role Services” page of the Add Role Services Wizard, select a ISAPI Filters and click “Next”.
• Now, will go to the Confirm Installation Selections page.
• Click Install and an ISAPI will be enabled.
• Now, will be redirected to the Results page.
• Click “Close”.

27. What is the default user name of the anonymous login in a IIS?

Ans:

The default user name of the anonymous login in an IIS is “IUSR_MachineName”.

28. Why use app pool recycling in IIS?

Ans:

App pool recycling is used in the IIS to free up to the consumed memory by the applications in an app pool.

29. Why need to debug IIS remotely?

Ans:

• If don’t have installed IIS on the development server.
• If the development server and a Build/Released/Hosting server are varient.
• If have multiple users and they need to debug simultaneously.

30. Which tool is used for a debugging IIS remotely?

Ans:

Use the tool named mavsmon.exe process to debug a IIS remotely. It was a first introduced to MS Visual Studio 2005.

31. What are the various security settings available in IIS?

Ans:

• Basic Authentication
• Digest Authentication
• Passport Authentication
• Integrated Windows Authentication
• Anonymous

32. What are the major functionalities of ISAPI filters in the IIS?

Ans:

In IIS, the ISAPI filters are majorly used to modify and an enhance the functionalities of IIS. These are also used to filter requests to find one to process, authenticate, and apply the input or output data encryption.

33. What is the use of enabling the pinging properties for the application pool in IIS?

Ans:

IIS has to monitor the health for the worker process periodically. It checks whether the worker process is idle or not, whether all worker processes are running properly, and whether it is the time to be recycle. By enabling the pinging properties, the activation process monitors to worker process performance, health, idle time etc.

34. What is the role of the protocol listener in IIS?

Ans:

• It is used to receive the protocol-specific requests from the client.
• It sends a requests to the client for processing.
• It also sends a responses back to the requestors.

35. What is the functionality of the HTTP.SYS in IIS?

Ans:

The HTTP.SYS is a protocol listener that is majrly used to receive the client requests, send them to IIS for processing, and finally send back to the client’s responses. HTTP.SYS is a subsection of the Kernel Mode and is the core component to receive and serve a HTTP requests and pass them off to the worker processes.

36. What are the major components of SVCHost.exe?

Ans:

WWW Publishing Service (W3SVC): It is the mediator of the HTTP.SYS.

Windows Activation Process (WAP): Windows Activation Process or WAP is used to keep the worker processes.

37. What is the role of a IIS Metabase in IIS?

Ans:

The IIS Metabase is majorly used to keep the settings and configuration data in IIS.

38. What are the various subsections of User mode in IIS?

Ans:

In IIS, the various subsections of User mode are Web Admin Service, Virtual Directory, and Application Pool.

39.What are the additional or enhanced security features in IIS 7.5?

Ans:

• Client certificate mapping
• IP security
• Request filtering
• URL authorization

40.what are the modules in IIS 7.0?

Ans:

• security module
• content module
• compression module
• caching module
• logging and diagnostic module

41. What are the various versions of IIS that have worked on?

Ans:

• Windows Server 2003- IIS 6.0
• Windows XP Professional – IIS 5.1
• Now based on the working experience that can say that have worked on IIS 5.1 and 6.0 or only IIS 7. Etc..

42. What is the Application Pool in IIS?

Ans:

Application pools are used to separate the sets of IIS worker processes that share the similar configuration and application boundaries. Application pools used to isolate the web application for better security, reliability, and availability and performance and maintain running without impacting each other . The worker process serves as the process boundary that separates every application pool so that when one worker process or application is having a problem or recycles, other applications or worker processes are not affected.One Application Pool can have more worker processes Also.

43. What is ISAPI in IIS?

Ans:

• ISAPI is an open specification introduced by the microsoft.
• It is faster and very flexible than CGI for extending IIS.

44. What is the Role of IIS ?

Ans:

Visual studio has its own ASP.NET Engine which is capable enough to run Asp.net web applications from the visual studio. So just click on the Run button to start an application.Now this is the scenario of the local environment. But If I want to host it on the server from where all users can access the sites then IIS comes into the picture. IIS offers a redesigned WWW architecture that can help to achieve better performance, reliability, scalability, and security for the Web sites. IIS can encourage the following Protocol HTTP/HTTPS, FTP, FTPS, SMTP Etc. need to host the site on an IIS, when a request comes to from the client it first hits the IIS Server, then the server passes it to the ASP.NET worker process to execute. Then the response also passes to the client via IIS itself.

45. What are the various security settings available in the IIS ?

Ans:

• Anonymous
• Integrated Windows Authentication
• Basic Authentication
• Digest Authentication
• Passport Authentication

46. What is the Name of the Default Application Pool in IIS ?

Ans:

Default application pool named : A DefaultAppPool

47. What is the Role of a Http.Sys in IIS ?

Ans:

HTTP.SYS is the kernel level components of the IIS. All client requests come from a client hit the HTTP.Sys of Kernel level. HTTP.SYS then made a queue for each and every request for each and individual application pool based on a request.Whenever create any application pool an IIS automatically registered the pool with HTTP.SYS to identify the specific application during the request processing.

48. What are the various types of Identity available in IIS 6.0?

Ans:

1. 1.Local System
2. 2.Local Services
3. 3.NetworkServices

49.What exactly does HTTP.sys do in IIS?

Ans:

• HTTP.sys is known as the “HTTP Protocol Stack” or “Http Listener Process”
• It is Implemented as a kernel-mode device driver. It is the core component to receive and serve the HTTP requests and pass them off to the worker processes.
• When create a Web site, IIS registered the site with HTTP.sys
• Other than retrieving the stored response from its an internal cache,
• HTTP.sys does not process the requests that it receives.

50. What is the Recycling of Application Pool?

Ans:

Recycling Application pool means recycling the Worker process (w3wp.exe ) and the memory used for a web application.There are 2 types of recycling related with an Application pool:

1. 1. Recycling Worker Process – Predefined Settings
2. 2. Recycling Worker Process – Based on Memory

51. What are the ISAPI filters in IIS?

Ans:

• ISAPI filters are DLL files that can be used to change and enhance the functionality provided by the IIS
• ISAPI filters always run on an IIS server, filtering each request until they find one they require to process
• Mostly used for an Authentication and Encryption of the i/p or o/p data for the site locally or all the apps globally

52.From where can I change the ASP.NET Version in IIS?

Ans:

This can be changed from Virtual Directory properties. First open the Properties of Virtual Directory > GoTo ASP.NET Version Tab.There can be the ASP.NET Version.

53. What is the default user name of the anonymous login in IIS?

Ans:

In IIS, an anonymous user will be a given with the user name of “IUSR_MachineName “

54. How can I take back-ups in the IIS Server?

Ans:

Step 1: In the IIS (inetmgr), right click on a “Computer” icon under “Internet Information Services” . Click the “All Tasks” and select a “Backup/Restore Configuration”.

Step 2: Click on the button “Create backup”. Give Name for a backup file. If you need encryption, enable the encryption option and give an UserName and Password and then click OK.

55. What is an IIS metabase? And In which format IIS saves configurations?

Ans:

IIS metabase is a special database which is used to keep the settings and configurations data for the IIS. In simple terms, it is the configuration of base for IIS (Metabase.xml).

56. What are the major components of SVCHost.exe ?

Ans:

• Major components for SVCHost.exe are WWW Publishing Service (W3SVC) and alsoWindows Activation Process (WAP) .
• W3SVC is the mediator of a HTTP.SYS and Windows Activation Process. Windows Activation Process keeps the worker processes.

57. What are the various ways that we can host sites on IIS ?

Ans:

• Can host site on the IIS either creating Virtual Directory through IIS manager or Using Folder Web Sharing .
• Apart from that the Visual studio provide some inbuilt features to host a site on IIS like using Publishing the web site , Using Copy web Tool or generating Virtual directory during a creating the project by choosing a Location as HTTP

58. How does the IIS process an ASP.net request ?

Ans:

When client requests for the aspx pages, request comes to the kernel level off IIS means HTTP.SYS . HTTP.SYS receives a request and based on an application pool name [ Which is already registered with the HTTP.SYS ] it sends a request to the worker process. Windows Activation process works as a mediator of them. w3wp.exe loads “aspnet_isapi.dll” files to initiate the HTTPRuntime . HTTPRuntime makes HTTPApplication objects and all requests are passed through the HTTPModule and finally reached to a HttpHandler . This is the for request pipeline. After the end of the Request pipeline ASP.NET Page life cycle starts.

59. What are the benefits of the modular architecture in IIS7?

Ans:

Some of the benefits of the modular architecture include Componentization, Extensibility, and ASP.NET Integration.

60. What does Componentization mean in IIS?

Ans:

Componentization meant the availability of the web server features as standalone components can simply add, remove, or replace a component.

61. What extra care has to be taken while installing the native module?

Ans:

Need to install only a native modules that come from the trusted source. This is because any resource in a server worker process has unrestricted access to the native modules.

62. What are the advantages of an AppCmd in IIS7?

Ans:

The advantages of AppCmd are – it offers server control without the need for the graphical administration tools. Besides, it enabled us to automate the server management quickly. Also, don’t require me to write any code.

63. How do I make and restore backups of the global server configurations in IIS?

Ans:

Using AppCmd, can make and restore the backups of the global server configurations in IIS.

64. How do I ensure content security in IIS?

Ans:

Can ensure content security by using the ACL (Access Control List). It offers a allowing or denying permissions to the required identities.

65. What does the typically shared hosting environment consist of in IIS?

Ans:

Front-end servers – to route requests to the content locations

Back-end web servers – to save and index the content

Web management services – to enabled the customers to published and manage content speedily

66. What happens if a kernel-mode cache is to be turned off?

Ans:

The impact may not be noticeable if the load is 100 requests per second. However, if it is around 1000 requests per second, the kernel caching will certainly be missed. Ultimately, it all depends on a server load.

67. What are the advantages of Componentization?

Ans:

• Reduction on the amount of a memory the server uses
• Performance improvement
• Increased server security with the removal of all an unused server features

68. What is the Application Host? config in IIS?

Ans:

• Applications
• Virtual directories and application pools
• Definitions of all sites
• Global defaults for the web server settings

69. What is the purpose of the App pool recycling in IIS?

Ans:

The purpose of App pool recycling is to free up the memory, which is consumed by applications in the app pool.

70. With which tool, can I debug IIS remotely?

Ans:

Can debug IIS remotely by using the mavsmon.exe process, which belongs to MS Visual Studio 2005.

71. What are the functionalities of the ISAPI filters in IIS?

Ans:

Some of the functionalities of the ISAPI filters included modifying and enhancing the functionality of IIS, filtering the requests to find the one, which is to be processed, and an authentication and also encryption of the input or output data.

72. Which are the functions that the protocol listener serves in IIS?

Ans:

• Receiving the protocol-specific requests from a client
• Sending the requests to a client for processing
• Sending a responses back to the requestors

73. HTTP.SYS is the subsection of which mode?

Ans:

HTTP.SYS is the subsection of a Kernel Mode.

74. What is the functionality of the HTTP.SYS?

Ans:

HTTP.SYS, which is the protocol listener, receives client requests, sends them to IIS for the processing, and finally returns a response to the client.

75. Which are the subsections of the User mode?

Ans:

The subsections of the User mode are Web Admin Service, Virtual Directory, and Application Pool.

76. What is an IUSR_MachineName in the IIS?

Ans:

It is the default for user names given to the anonymous user when login into IIS.

77. What purpose does the IIS Metabase serve in IIS?

Ans:

IIS Metabase serves the purpose of keeping the settings and configuration data.

78. What are the various native modules of the IIS?

Ans:

The native modules of the IIS include – HTTP modules, Security modules, Content modules, Compression modules, Caching modules, Logging, and Diagnostic modules, and Managed the support modules. All these modules are available with the full installation of IIS 7 and later.

79. Which are the protocols that IIS supports?

Ans:

The protocols that IIS supports included HTTP/HTTPS, FTP, FTPS, SMTP, etc.

80. What are the new features in the IIS 8.5?

Ans:

The new features in the IIS 8.5 include enhanced logging capabilities and also dynamic site activation.

81. What is the virtual directory?

Ans:

It is the name of the directory, which is mapped to be a physical directory in a local server.

82. What are log files?

Ans:

Log files record various actions on a server, which included the date, time, IP address, and volume of transmitted data.

83. HTTP.SYS is a subsection of which mode?

Ans:

HTTP.SYS is a subsection of Kernel Mode.

84. What is the functionality of a HTTP.SYS?

Ans:

HTTP.SYS, which is the protocol listener, receives client requests, sends them to the IIS for processing, and finally returns the responses to the client.

85. Which are subsections of User mode?

Ans:

The subsections of the User mode such as Web Admin Service, Virtual Directory, and Application Pool.

86. What Are The Security Authentication In the Iis ?

Ans:

1. 1.Anonymous
2. 2.Integrated Windows Authentication
3. 3.Basic Authentication
4. 4.Digest Authentication
5. 5.Passport Authentication

87. Default Iis in Port Numbers?

Ans:

• HTTP – 80
• SSL – 443
• FTP – 21
• SMTP – 25
• POP3 – 110
• IMAP – 143
• NNTP – 119
• LDAP – 89
• Other Port Number
• DNS – 53
• DHCP – 67

88.Default Iis Services?

Ans:

1. 1. www services (World Wide Web)
2. 2. FTP services (File Transfer Protocol)
3. 3. SMTP services (Simple Mail Transfer Protocol)
4. 4. NNTP services (Network News Transfer Protocol)

89. What Are The Default Permissions For a Virtual Directory?

Ans:

1. 1.Read
2. 2.Write
3. 3.Execute
4. 4.Browse
5. 5.Run Scripts

90. How To Save an Application Pool Settings In A File?

Ans:

• Right click on the Application Pool ->All Task ->Save Configuration to a File.
• It will save a configuration file in the xml format.

91. What Are The Execution Permission For The Virtual Directory?

Ans:

1. 1.None
2. 2.Scripts Only
3. 3.Scripts and Executable

92. What Are the Script Files In IIS?

Ans:

iisweb.vsb – Create,Delete,start,stop,list websites

iisftp.vsb – Create,Delete,start,stop,List FTP sites

iisdir.vsb – Create,Delete,start,stop,List Virtual Directories

93. How User Can Attach the Particular Worker Process To Application When More Worker Processes Are Running In IIS?

Ans:

First identify an Application pool name and process ID by using cscript iisapi.vbs script.Later attach the process from Visual Studio IDE.

94. How To Open a IIS Manager ?

Ans:

1. 1. From Run -> inetmgr
2. 2. Start -> Programs -> Administrative tools

95. Unique Properties Of the App Pool In IIS?

Ans:

1. 1.Recycling Process
2. 2.Performance
3. 3.Health
4. 4.Process Identity

96. What Are The Different Application Pools In IIS ?

Ans:

1. 1. DefaultAppPool (Integrated)
2. 2. ClassicAppPool

97. Which are the protocols that IIS supports?

Ans:

The protocols that IIS supports included HTTP/HTTPS, FTP, FTPS, and SMTP, etc.

98. What are the new features in the IIS 8.5?

Ans:

The new features in the IIS 8.5 includes enhanced logging capabilities and dynamic site activation.

99. What is the purpose of an Application Pool in IIS?

Ans:

Application Pool separates applications from each other and simplifies management. It explains a group of settings for the worker processes, which carry out the request processing for all of the applications in a pool.

100. Do you know what a web garden is?

Ans:

By default Every Application Pool runs with the Single Worker Process (W3Wp.exe). can assign a multiple Worker Process With a Single Application Pool. An Application Poll with the multiple Worker process called a Web Gardens. Every Worker Process Should have there own Thread and Own Memory space.