title | description | ms.date | ms.topic | author | ms.author | manager | ms.subservice |
---|---|---|---|---|---|---|---|
Remote debug ASP.NET on an IIS computer |
Learn how to set up and configure a Visual Studio ASP.NET MVC 4.8 application, deploy it to IIS, and attach the remote debugger from Visual Studio. |
04/23/2024 |
conceptual |
mikejo5000 |
mikejo |
mijacobs |
debug-diagnostics |
To debug an ASP.NET application that has been deployed to IIS, install and run the remote tools on the computer where you deployed your app, and then attach to your running app from Visual Studio.
This guide explains how to set up and configure a Visual Studio ASP.NET MVC 4.8 application, deploy it to IIS, and attach the remote debugger from Visual Studio.
Note
To remote debug ASP.NET Core instead, see Remote Debug ASP.NET Core on an IIS Computer. For Azure App Service, see Remote debug ASP.NET Core on Azure or, for Visual Studio Enterprise, use the Snapshot Debugger (.NET 4.6.1 required).
Visual Studio 2019 or a later version is required to follow the steps shown in this article.
These procedures have been tested on these server configurations:
- Windows Server 2022 and IIS 10
- Windows Server 2012 R2 and IIS 8 (For Windows Server 2008 R2, the server steps are different)
The remote debugger is supported on Windows Server starting with Windows Server 2008 Service Pack 2. For a complete list of requirements, see Requirements.
Note
Debugging between two computers connected through a proxy is not supported. Debugging over a high latency or low-bandwidth connection, such as dialup Internet, or over the Internet across countries/regions is not recommended and might fail or be unacceptably slow.
This article includes steps on setting up a basic configuration of IIS on Windows server and deploying the app from Visual Studio. These steps are included to make sure that the server has required components installed, that the app can run correctly, and that you're ready to remote debug.
-
If your app is running in IIS and you just want to download the remote debugger and start debugging, go to Download and Install the remote tools on Windows Server.
-
If you want help with ensuring your app is set up, deployed, and running correctly in IIS so that you can debug, follow all the steps in this article.
-
Create a new MVC ASP.NET application.
In Visual Studio, choose File > Start window to open the Start window, and then choose Create a new project. In the search box, type asp.net framework, and then choose ASP.NET Web Application (.NET Framework). In the dialog box that appears, name the project MyASPApp, choose ASP.NET Framework 4.8, and then choose Create.
Select MVC and choose Create.
-
Open the HomeController.cs file in the Controllers folder and set a breakpoint in the
return View;
statement in thePrivacy
method.In older templates, open the Privacy.cshtml.cs file and set a breakpoint in the
OnGet
method.
[!INCLUDE remote-debugger-install-iis-role]
If you're using an older version of Windows Server, you might need to add some domains as trusted sites to enable you to download some of the web server components. Add the trusted sites by going to Internet Options > Security > Trusted Sites > Sites. Add the following domains.
- microsoft.com
- go.microsoft.com
- download.microsoft.com
- iis.net
When you download the software, you might get requests to grant permission to load various web site scripts and resources. Some of these resources aren't required, but to simplify the process, select Add when prompted.
If you want more detailed information to install ASP.NET on IIS, see IIS 8.0 Using ASP.NET 3.5 and ASP.NET 4.5.
Note
The Web Platform Installer reached End-of-Life on 7/1/22. For more information, see Web Platform Installer - End of support and sunsetting the product/application feed. You can directly install ASP.NET 4.8 from IIS.
-
In the left pane of Server Manager, select IIS. Right-click the server and select Add Roles and Features.
-
In the wizard, advance to the Features section and install ASP.NET 4.8.
[!NOTE] If you are using Windows Server 2008 R2, install ASP.NET 4 instead using this command:
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -ir
-
Restart the system (or execute net stop was /y followed by net start w3svc from a command prompt to pick up a change to the system PATH).
If you need help with deploying the app to IIS, consider these options:
-
Deploy by creating a publish settings file in IIS and importing the settings in Visual Studio. In some scenarios, this is a fast way to deploy your app. When you create the publish settings file, permissions are automatically set up in IIS.
-
Deploy by publishing to a local folder and copying the output by a preferred method to a prepared app folder on IIS.
You can use this option to create a publish settings file and import it into Visual Studio.
Note
If you want to configure Web Deploy manually instead of importing the publish settings, you will need to make sure that an app folder on the server is configured with the correct values and permissions (see Configure ASP.NET Web site).
[!INCLUDE install-web-deploy-with-hosting-server]
[!INCLUDE install-web-deploy-with-hosting-server]
[!INCLUDE install-web-deploy-with-hosting-server]
After the app deploys successfully, it should start automatically. If the app doesn't start after deployment, start the app in IIS to verify that it runs correctly.
When you're ready, switch to a debug configuration.
Important
If you choose to debug a Release configuration, you disable debugging in the web.config file when you publish.
::: moniker range=">=vs-2022"
- Select More Options > Edit to edit the profile, and then select Settings.
- Select a Debug configuration, and then select Remove additional files at destination under the File Publish options.
- Select Save and then republish the app. ::: moniker-end
::: moniker range="vs-2019"
- Select Edit to edit the profile, and then select Settings.
- Select a Debug configuration, and then select Remove additional files at destination under the File Publish options.
- Select Save and then republish the app. ::: moniker-end
Warning
Using username and password credentials (basic authentication) is not the most secure method of authentication. Whenever possible, use alternative methods. For example, consider publishing to a package from Visual Studio, and then use WebDeploy.exe from a command line to deploy the package. With that method, you can use IIS Manager to configure authorized Windows users who can publish to the web server, and run WebDeploy.exe under that Windows user account. See Installing and Configuring Web Deploy on IIS 8.0 or Later. If you do use password credentials, be sure to use a strong password, and secure the password from being leaked or shared.
You can use this option to deploy your app if you want to copy the app to IIS using PowerShell, RoboCopy, or you want to manually copy the files.
-
Open Windows Explorer and create a new folder, C:\Publish, where you later deploy the ASP.NET project.
-
If it's not already open, open the Internet Information Services (IIS) Manager. (In the left pane of Server Manager, select IIS. Right-click the server and select Internet Information Services (IIS) Manager.)
-
Under Connections in the left pane, go to Sites.
-
Select the Default Web Site, choose Basic Settings, and set the Physical path to C:\Publish.
-
Right-click the Default Web Site node and select Add Application.
-
Set the Alias field to MyASPApp, accept the default Application Pool (DefaultAppPool), and set the Physical path to C:\Publish.
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Under Connections, select Application Pools. Open DefaultAppPool and set the Application pool field to ASP.NET v4.0 (ASP.NET 4.5 isn't an option for the Application pool).
-
With the site selected in the IIS Manager, choose Edit Permissions, and make sure that IUSR, IIS_IUSRS, or the user configured for the Application Pool is an authorized user with Read & Execute rights.
If you don't see one of these users with access, go through steps to add IUSR as a user with Read & Execute rights.
Important
For security information related to the built-in accounts, see Understanding Built-In User and Group Accounts in IIS 7.
You can also publish and deploy the app using the file system or other tools.
For ASP.NET 4.8, make sure the web.config file lists the correct version of .NET.
-
If you're targeting ASP.NET 4.8, make sure this version value is listed in the web.config file:
<system.web> <compilation debug="true" targetFramework="4.8" /> <httpRuntime targetFramework="4.8" /> <httpModules> <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" /> </httpModules> </system.web> ```
-
If you install ASP.NET 4 instead of 4.8, the version value should be specified as 4.0 in the web.config file.
Follow these steps to publish and deploy the app:
[!INCLUDE remote-debugger-deploy-app-local]
Download the version of the remote tools that matches your version of Visual Studio.
[!INCLUDE remote-debugger-download]
[!INCLUDE remote-debugger-configuration]
Note
If you need to add permissions for additional users, change the authentication mode, or port number for the remote debugger, see Configure the remote debugger.
For information on running the remote debugger as a service, see Run the remote debugger as a service.
::: moniker range=">=vs-2022"
Starting in Visual Studio 2022 version 17.10 Preview 2, the Attach to Process dialog box has changed. If you need instructions that match the older dialog box, switch to the Visual Studio 2019 view (upper left version selector in the article).
-
On the Visual Studio computer, open the solution that you're trying to debug (MyASPApp if you're following all the steps in this article).
-
In Visual Studio, select Debug > Attach to Process (Ctrl + Alt + P).
[!TIP] In Visual Studio 2017 and later versions, you can reattach to the same process you previously attached to by using Debug > Reattach to Process... (Shift + Alt + P).
-
Set the Connection Type to Remote (Windows).
The Connection Target option appears.
Set the Connection Target to <remote computer name> and press Enter.
Verify that Visual Studio adds the required port to the computer name, which appears in the format: <remote computer name>:port
On Visual Studio 2022, you should see <remote computer name>:4026
The port is required. If you don't see the port number, add it manually. ::: moniker-end
::: moniker range="vs-2019"
-
On the Visual Studio computer, open the solution that you're trying to debug (MyASPApp if you're following all the steps in this article).
-
In Visual Studio, select Debug > Attach to Process (Ctrl + Alt + P).
[!TIP] In Visual Studio 2017 and later versions, you can reattach to the same process you previously attached to by using Debug > Reattach to Process... (Shift + Alt + P).
-
Set the Qualifier field to <remote computer name> and press Enter.
Verify that Visual Studio adds the required port to the computer name, which appears in the format: <remote computer name>:port
On Visual Studio 2019, you should see <remote computer name>:4024
The port is required. If you don't see the port number, add it manually. ::: moniker-end
-
Select Refresh.
You should see some processes appear in the Available Processes window.
If you don't see any processes, try using the IP address instead of the remote computer name (the port is required). You can use
ipconfig
in a command line to get the IPv4 address.If you want to use the Find button, you might need to open outbound UDP port 3702 on the server.
-
Check Show processes from all users.
-
Type the first letter of a process name to quickly find w3wp.exe for ASP.NET 4.5.
If you have multiple processes showing w3wp.exe, check the User Name column. In some scenarios, the User Name column shows your app pool name, such as IIS APPPOOL\DefaultAppPool. If you see the App Pool, an easy way to identify the correct process is to create a new named App Pool for the app instance you want to debug, and then you can find it easily in the User Name column.
::: moniker range=">=vs-2022"
::: moniker-end ::: moniker range="vs-2019"
::: moniker-end
-
Select Attach.
-
Open the remote computer's website. In a browser, go to http://<remote computer name>.
You should see the ASP.NET web page.
-
In the running ASP.NET application, select the link to the Privacy page.
The breakpoint should be hit in Visual Studio.
If you're unable to attach or hit the breakpoint, see Troubleshoot remote debugging.
- If you can't connect to the host using the host name, try the IP address instead.
- Make sure the required ports are open on the remote server.
- Verify that the version of ASP.NET used in your app is the same as the version you installed on the server. For your app, you can view and set the version in the Properties page. To set the app to a different version, that version must be installed.
- If the app tried to open, but you see a certificate warning, choose to trust the site. If you already closed the warning, you can edit the publishing profile, a *.pubxml file, in your project and add the following element (for test only):
<AllowUntrustedCertificate>true</AllowUntrustedCertificate>
- After it's deployed, start the app in IIS to test that it deployed correctly.
- Check the Output window in Visual Studio for status information, and check your error messages.
In most setups, required ports are opened by the installation of ASP.NET and the remote debugger. However, you might need to verify that ports are open.
Note
On an Azure VM, you must open ports through the Network security group.
Required ports:
- 80: Required for IIS.
::: moniker range=">=vs-2022"
-
4026: Required for remote debugging from Visual Studio 2022 (see Remote Debugger Port Assignments for more information). ::: moniker-end
-
4024: Required for remote debugging from Visual Studio 2019 (see Remote Debugger Port Assignments for more information).
-
UDP 3702: (Optional) Discovery port enables you to the Find button when attaching to the remote debugger in Visual Studio.
In addition, these ports should already be opened by the ASP.NET installation:
- 8172: (Optional) Required for Web Deploy to deploy the app from Visual Studio.
-
To open a port on Windows Server, open the Start menu, search for Windows Defender Firewall or Windows Firewall with Advanced Security.
For Windows Defender Firewall, choose Advanced settings.
-
Then choose Inbound Rules > New Rule > Port. Choose Next and under Specific local ports, enter the port number, select Next, then Allow the Connection, select Next, and add the name (IIS, Web Deploy, or msvsmon) for the Inbound Rule.
If you want more details on configuring Windows Firewall, see Configure the Windows Firewall for Remote Debugging.
-
Create more rules for the other required ports.