Internet Information Services (IIS) is a Windows host for web applications. An ASP.NET Core app can be published to an IIS website so users can reach it at the website’s configured URL. IIS is one deployment option, not a requirement for ASP.NET Core. section 27.0 section 27.2.1
IIS was tightly coupled to older ASP.NET, helping tie that framework to Windows. ASP.NET Core is cross-platform. When deployed to IIS, it uses the ASP.NET Core Module to connect IIS and the application. section 2.2 section 27.2.1
For a basic ASP.NET Core deployment on Windows:
- Install the ASP.NET Core Windows Hosting Bundle. It includes the .NET Runtime, ASP.NET Core Runtime, and IIS AspNetCore Module; install it on a development machine too if you run IIS there. section 27.2.1
- Create an IIS application pool with its .NET CLR version set to No Managed Code. Unlike older ASP.NET, ASP.NET Core does not use a .NET Framework managed pool. section 27.2.1
- Add an IIS website, select that pool, and set the website name, published-files folder, and URL. The application pool needs permission to access the publish folder. section 27.2.1
- Publish the app, then copy its published files to the website’s hosting folder. section 27.2 section 27.2.2
Publish before copying
Run `dotnet publish --output publish_folder --configuration Release`, then copy the output to the folder configured for the IIS website. A local example uses IIS at `http://localhost:81`. section 27.2.2
IIS integration is added automatically when an app uses WebApplicationBuilder. A custom builder must add it explicitly: UseIIS() supports in-process hosting, while UseIISIntegration() supports out-of-process hosting. In-process hosting has been the IIS default since ASP.NET Core 3.0; the app runs inside the IIS process rather than in a separate process behind it. section 27.2.2
This setup gets an app running; it is not a complete guide to IIS configuration or troubleshooting. IIS can manage an ASP.NET Core deployment on Windows, while other hosting choices remain available. section 27.2 section 27.0
