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Let’s start your career as Windows Server Administrator and prepare yourself for Windows Interview Questions with these latest Microsoft IIS Interview Questions and Answers.

In Microsoft IIS Administrator interview you won’t be asked for full form of iis and instead of iis full form you can be asked to answer scenario based questions which can be easy for experienced IIS Administrator if you are confident with basics of IIS Administration concepts. We have made this IIS Interview Questions and Answers keeping both pool of professionals, experienced and freshers. These Microsoft IIS admin interview questions are applicable to IIS 6.0, IIS 7.0, IIS 7.5, IIS 8.0 and IIS 8.5.

For experienced IIS Administrator, IIS Interview questions can be scenario based. Read out this IIS Interview Questions and Answers thoroughly and map the scenario.

We will cover role and responsibility of IIS Administrator, Resume Sample of IIS Administrator in last section of this IIS questions and answers.

IIS Interview Questions and Answers

Q: – What is the Role of IIS ?

Visual studio having It own ASP.NET Engine which is capable enough to run Asp.net web application from visual studio. So we just click on Run button to start the application.Now this is the scenarios of local environment. But If we want to host it on server from where all user can access the sites then IIS comes into the picture. IIS provides a redesigned WWW architecture that can help you achieve better performance, reliability, scalability, and security for our Web sites. IIS can support following Protocol HTTP/HTTPS, FTP, FTPS, SMTP Etc. We need to host the site on IIS, when request comes from client it first hits the IIS Server, then the server passed it to ASP.NET worker process to execute. Then the response also passes to client via IIS itself.Note only Hosting of Site we can create our FTP Server, SMTP Server using IIS itself.There are different version of IIS available like 5.1, 6.0, 7.0 etc.

Q: – Provide IIS service names.

  • WWW Services
  • FTP Services
  • SMTP Services
  • NNTP Services

Q: – What are IIS port numbers ?

  • HTTP (Default port of IIS) : 80
  • SSL: 443
  • FTP: 21
  • SMTP: 25
  • POP2: 109
  • POP3: 110
  • IMAP: 143
  • NNTP: 119
  • LDAP: 89
  • DNS: 53
  • DHCP: 67

Q: – How to open IIS Manger ?

There are two ways to open IIS manger,

  • Run (Press Windows Key + R) -> Type, INETMGR
  • open IIS Manager from control panel > Administrative tools

Q: – What are the main layers of IIS Architecture ?

IIS having mainly two layer Kernel Mode and User Mode

  • Kernal Mode : HTTP.SYS
  • User Mode : Web Admin Services, Virtual Directory, Application Pool

Q: – What is the Role of Http.Sys in IIS ?

This is one of the most asked IIS Interview Question in IIS Interview HTTP.SYS is the kernel level components of IIS. All client request comes from client hit the HTTP.Sys of Kernel level. HTTP.SYS then makes a queue for each and every request for each and individual application pool based on the request.Whenever we create any application pool IIS automatically registers the pool with HTTP.SYS to identify the particular during request processing.

Q: – How does IIS Process ASP.NET Requests ?

When client request for an aspx pages, request comes to kernel level off IIS means to HTTP.SYS. HTTP.SYS receives the request and based on the application pool name [ Which is already registred with the HTTP.SYS ] it send the request to worker process. Windows Activation process works as mediator of them. w3wp.exe loads aspnet_isapi.dll files to start the HTTPRuntime. HTTPRuntime creates HTTPApplication objects and all request are passed through HTTP Module and finally reached to HttpHandler. This is the request pipeline. After end of Request pipeline ASP.NET Page lifecycle starts.

Q: – What is an Application Pool in IIS Server ?

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

Q: – What is the Name of Default Application Pool in IIS ?

Default application pool named : DefaultAppPool

Q: – What is the properties of App Pool in IIS ?

  • Recycling
  • Perfomance
  • Health
  • Identity

Q: – What is the available Identity of an Application Pool ?

  • In IIS 6.0 – NetworkServices, LocalService, LocalSystem
  • In IIS 7.0 (and above) – NetworkServices, LocalService, LocalSystem, ApplicationPoolIdentity

Q: – What is Recycling of Application Pool ?

Recycling Application pool means recycle the Worker process (w3wp.exe) and the memory used for the web application.

There are two types of recycling related with Application pool.

  • Recycling Worker Process – Predefined Settings
  • Recycling Worker Process – Based on Memory

Q: – What are the worker process for IIS 5.1 and IIS 6.0 and IIS 7.0 ?

  • IIS 5.1 : aspnet_wp.exe
  • IIS 6.0 > w3wp.exe
  • IIS 7.0 (and beyond) : w3wp.exe

Q: – What are the main components of SVCHost.exe ?

Main components for SVCHost.exe are WWW Publishing Service (W3SVC) and Windows Activation Porcess (WAP) .

W3SVC is the mediator of HTTP.SYS and Windows Activation Process. Windows Activation Process maintain the worker processes.

Q: – What is the Role of Windows Activation Process in IIS ?

WAP is the Controller of Worker process under a Application Pool. Windows Activation Process which is managed by the worker process by starting, stopping and recycling the application pool. When to start, stop and Recycle should be defined on Application Pool Settings. Activation Process is also responsible for Health Monitor of Application Pool during runtime.

Q: – What is the default Identity of an Application Pool ?

Network Services.

Q: – What are the different type of application pool available in IIS 7.0 ?

  • DefaultAppPool (Integrated)
  • ClassicAppPool

Q: – What is App Pool and App Domain? What is the difference ?

Application pool and AppDomain , both of them can provide isolations, but use different approches. Application pool use the process to isolate the applications which works without .NET. But AppDomain is another isolation methods provided by .NET.

If your server host thousands of web sites, you wont use thousands of the application pool to isolate the web sites, just because, too many processes running will kill the OS. However, sometime you need application pool. One of the advantages for application pool is that you can config the identity for application pool. Also you have more flexible options to recycle the application pool. At least right now, IIS didn’t provide explicit options to recycle the app domain.

Q: – Where session data stores in case of “In-Proc” Session mode ?

Session data store inside process memory of worker process [w3wp.exe].

Q: – What is Web Farm ?

When we hosted our web Application on multiple web server under a load balancer call the Web Farm. This is generally used for heavy load web application where there are many user requests at a time. So When Web Application is hosted on Different IIS Server over a load balancer, Load balancer is responsible for distribute the load on different server.

Q: – What is Web Garden?

A Web garden is configured on a single server by specifying multiple worker processes for an application pool. Web farms use multiple physical servers for supporting a single Web site.

Q: – Where is the default location for IIS Log files ?


IMP : We can also change default IIS log location.

Q: – What is the use of aspnet_regiis -i command ?

This is used automatically register the .NET Framework with your IIS.

Q: – How to check Installed .Net Version on IIS

Press Windows Key + R, Type RUN and provide following command to know installed Dot Net version,

C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322>aspnet_regiis.exe –lv

Q: – How do I stop and restart Internet services?

Press Windows Key + R, Type RUN and provide following command to restart IIS Server,


Q: – What are the different security settings available in IIS ?

Q: –  What is Virtual Directory in IIS ?

A Virtual Folder or Virtual Directory is just a link to a physical folder somewhere on the server. This folder becomes part of the website structure and you can use the virtual directory in the path part of URLs. Code that executes in Virtual Directories will execute in the same “Application” as it’s parent.

Q: – What is difference between Virtual Directory and Web App in IIS ?

A Virtual Folder or Virtual Directory is just a link to a physical folder somewhere on the server. This folder becomes part of the website structure and you can use the virtual directory in the path part of URLs. Code that executes in Virtual Directories will execute in the same “Application” as it’s parent.

An Application is where the code that runs inside that “folder” has it’s own Session state and Application state. It is in effect a new standalone application living underneath the root application. For example, if you were to deploy an ASP.NET application into a site that had an Application folder called /myapp then that application would have it’s own application domain, session state, application state completely separate from another ASP.NET application running in /.

Q: – How we can create a Virtual Directory on IIS ?

  • Open IIS Configuration Manager
  • First of all Right Click on Default web sites > New > Virtual Directory.
  • Browse the Physical Path.
  • Set the properties.
  • Click on OK

Q: – What are the permission settings are available for Virtual Directory ?

  • Read
  • Run Scripts
  • Execute
  • Write
  • Browse

Q: – What are the different “Execution Permission” available for IIS for an virtual directory ?

There are three Execution Permission available.

  • None
  • Scripts Only
  • Scripts and Executable
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