Elastic Compute Service:Troubleshoot IIS website access issues

Causes

• Hidden detailed errors: By default, IIS displays a generic "500 Internal Server Error" page to remote clients to avoid exposing sensitive server information, such as code paths or database connection strings.

• Configuration or code defects: The root cause is typically a syntax error in the web.config file or an exception in the application code.

Solution

Enable Detailed Errors in IIS to display the specific error cause and line number in the browser. This helps you pinpoint the problem.

1. Log on to the ECS instance.

   1. Go to ECS console - Instances. In the top navigation bar, select the target region and resource group.

   2. Go to the details page of the target instance, click Connect, and select Workbench. Set the connection method to Terminal, enter the username and password, and then log on to the graphical terminal page.

2. Open IIS Manager.

   1. Click Start and select Server Manager.

   2. In Server Manager, select Tools > Internet Information Services (IIS) Manager.

3. Enable detailed errors.

   1. In the navigation pane on the left of the Internet Information Services (IIS) Manager page, click the target website.

   2. In the IIS section, double-click Error Pages.

      

   3. In the Actions pane, click Edit Feature Settings..., select Detailed errors, then click OK.

4. Access the website to view the detailed error message.

   Press Ctrl+F5 to force a refresh. The browser now displays a detailed error message that points to the exact configuration file (such as web.config) and line number causing the issue. Use this information to correct the corresponding configuration file or application code.

1. Log on to the ECS instance.

   1. Go to ECS console - Instances. In the top navigation bar, select the target region and resource group.

   2. Go to the details page of the target instance, click Connect, and select Workbench. Set the connection method to Terminal, enter the username and password, and then log on to the graphical terminal page.

2. Open IIS Manager.

   1. Click Start and select Server Manager.

   2. In Server Manager, select Tools > Internet Information Services (IIS) Manager.

3. Configure the site binding.

   In the Internet Information Services (IIS) Manager navigation pane, select the target website and click Bindings... in the Actions pane. In the Site Bindings window, find the record with an empty Host name and double-click it. In the Edit Site Binding window, enter your domain name and click OK.

4. Verify that the website is accessible by domain name but not by public IP address.

1. Log on to the ECS instance.

   1. Go to ECS console - Instances. In the top navigation bar, select the target region and resource group.

   2. Go to the details page of the target instance, click Connect, and select Workbench. Set the connection method to Terminal, enter the username and password, and then log on to the graphical terminal page.

2. Open Command Prompt as an administrator.

   Click Start, type cmd, right-click Command Prompt, and select Run as administrator.

3. Check if the service port is in use.

   Get-NetTCPConnection -LocalPort <Port>

   The output includes the port status State and the owning process OwningProcess.

   LocalAddress    LocalPort RemoteAddress    RemotePort State     AppliedSetting OwningProcess
   ------------    --------- -------------    ---------- -----     -------------- -------------
   ::              80        ::               0          Listen                   4

   In this example, process ID 4 is using port 80.

4. Find the application by its PID.

   Replace <PID> with the process ID shown in the OwningProcess column from the previous step.

   Get-Process -Id <PID>

5. Resolve the port conflict.

   • Stop the process that is using the port.

     If you confirm that the program using the port can be closed, use the taskkill command to terminate the process:

     taskkill <PID>

   • Change the application's port.

     To minimize port conflicts, use a port in the registered range (8000–49151).

     1. Click Start, select Server Manager. In Server Manager, select Tools > Internet Information Services (IIS) Manager.

     2. In the navigation pane on the left of the Internet Information Services (IIS) Manager page, click the target website, then click Bindings... in the Actions pane.

     3. In the Site Bindings window, select an existing binding record, click Edit..., modify the port, and then click OK.

6. Restart IIS.

   iisreset /noforce

7. Verify that the website is accessible.

Causes

• Missing default document: The website's root directory or the accessed subdirectory does not have a default entry file (such as index.html or default.aspx) configured.

• Directory browsing disabled: For security, IIS prohibits listing directory contents by default. This setting triggers a 403.14 error when a default document cannot be found.

Solutions

Cause

IIS relies on Handler Mappings to determine how to process requests for specific file types, such as .aspx files. This error occurs when the .NET Framework is installed in the wrong order or its registration in IIS is corrupted or missing, preventing IIS from finding the correct component to handle ASP.NET requests.

Solution

Use the aspnet_regiis.exe tool to re-register the correct .NET Framework version in IIS. This action repairs the corrupted handler mappings.

1. Click Start, type cmd, right-click Command Prompt, and select Run as administrator.

2. Navigate to the Framework directory.

   The aspnet_regiis.exe tool resides in the .NET Framework installation directory.

   It is typically located in the C:\Windows\Microsoft.NET\Framework64 directory. For example, for .NET Framework 4.x:

   cd /d C:\Windows\Microsoft.NET\Framework64\v4.0.30319

3. Uninstall ASP.NET.

   aspnet_regiis.exe -u

4. Install and register ASP.NET with IIS.

   aspnet_regiis.exe -i

5. Restart IIS.

   iisreset /noforce

6. Verify that the website is accessible.

Cause

This error occurs when the FTP client is configured to use FTPS (FTP over SSL/TLS) for a secure connection, but the FTP site in IIS is not configured to allow SSL connections. The server then rejects the SSL/TLS handshake request from the client.

Solution

Check and enable the SSL connection policy for the FTP site in IIS to match the client's security requirements.

1. Log on to the ECS instance.

   1. Go to ECS console - Instances. In the top navigation bar, select the target region and resource group.

   2. Go to the details page of the target instance, click Connect, and select Workbench. Set the connection method to Terminal, enter the username and password, and then log on to the graphical terminal page.

2. Open IIS Manager.

   1. Click Start and select Server Manager.

   2. In Server Manager, select Tools > Internet Information Services (IIS) Manager.

3. Configure the FTP site's SSL policy.

   1. Click the target FTP site. In the FTP section of the home page, double-click FTP SSL Settings.

      

   2. In the FTP SSL Settings section, set the SSL Policy to Allow SSL connections, then click Apply in the Actions pane.

      

4. Verify that the FTP site is accessible.

Causes

The IIS server received an HTTP request but could not find a configured site that matched the hostname in the request header. This error has the following common causes:

• Hostname not bound: The target website does not have a binding for the requested domain name.

• Incorrect binding information: The website has a hostname binding, but it contains a spelling error or is bound to the wrong IP address or port.

• Binding conflict: The domain name is already bound to another site in IIS, causing a request routing conflict.

Solution

Check and correctly configure the target site's bindings to ensure the domain name used for access matches the site's configuration.

1. Log on to the ECS instance.

   1. Go to ECS console - Instances. In the top navigation bar, select the target region and resource group.

   2. Go to the details page of the target instance, click Connect, and select Workbench. Set the connection method to Terminal, enter the username and password, and then log on to the graphical terminal page.

2. Open IIS Manager.

   1. Click Start and select Server Manager.

   2. In Server Manager, select Tools > Internet Information Services (IIS) Manager.

3. Check and configure site bindings.

   1. In the navigation pane on the left of the Internet Information Services (IIS) Manager page, click the target website, then click Bindings... in the Actions pane.

      

   2. On the Site Bindings page, either add a new domain name binding or check if the existing binding information is correct.

      • Add a new binding.

        1. On the Site Bindings page, click Add....

        2. On the Add Site Binding page, enter the website's domain name in the Host name field, then click OK.

      • View or modify an existing binding.

        1. On the Site Bindings page, double-click the existing binding record.

        2. On the Edit Site Binding page, review the binding information.

           If you need to modify the domain name, edit the Host name and click OK.

4. Verify that the website is accessible.

Cause

A malformed or unrecognized XML element in the ApplicationHost.config or Web.config file causes this error.

ApplicationHost.config serves as the server's root configuration file, defining global defaults and server-level settings.

The Web.config file provides application-level configuration, used to override or extend settings inherited from a higher level.

Solution

1. Log on to the ECS instance.

   1. Go to ECS console - Instances. In the top navigation bar, select the target region and resource group.

   2. Go to the details page of the target instance, click Connect, and select Workbench. Set the connection method to Terminal, enter the username and password, and then log on to the graphical terminal page.

2. Open IIS Manager.

   1. Click Start and select Server Manager.

   2. In Server Manager, select Tools > Internet Information Services (IIS) Manager.

3. Check the web.config file.

   1. In the navigation pane on the left of the Internet Information Services (IIS) Manager page, click the target website, then click Explore in the Actions pane to open the site's directory.

      

   2. Open the web.config file in the site directory. Review the file and correct any errors, referring to the IIS Configuration Reference.

4. Check the ApplicationHost.config file.

   Go to the C:\Windows\System32\inetsrv\config\ folder and open the ApplicationHost.config file. Review the file and correct any errors, referring to the Introduction to ApplicationHost.config.

5. Open Command Prompt and restart IIS.

   iisreset /noforce

6. Verify that the website is accessible.