When working with IIS 8 on Windows Server 2012, you might notice that Basic Authentication doesn't appear in the Authentication pane by default. This isn't a bug - it's simply because the feature isn't installed. IIS 8 follows a modular approach where many authentication methods require separate installation.

Before proceeding, ensure you have:

• Administrative privileges on the server
• Windows Server 2012 with IIS 8 installed
• Access to Server Manager

Open Server Manager and follow these steps:

1. Click "Add roles and features"
2. Select "Role-based or feature-based installation"
3. Choose your server from the server pool
4. Navigate to:
   Server Roles > Web Server (IIS) > Web Server > Security
5. Check "Basic Authentication"
6. Click Next, then Install

Once installed:

1. Open IIS Manager
2. Select your site in the Connections pane
3. Double-click "Authentication"
4. Right-click "Basic Authentication" and select "Enable"

After enabling, right-click Basic Authentication and select "Edit" to configure:

<location path="YourSite">
  <system.webServer>
    <security>
      <authentication>
        <basicAuthentication enabled="true" 
                             realm="YourRealm" 
                             defaultLogonDomain="YOURDOMAIN" />
      </authentication>
    </security>
  </system.webServer>
</location>

Since Basic Authentication transmits credentials in base64 encoding (not encryption):

• Always use HTTPS with Basic Authentication
• Consider implementing IP restrictions
• Set appropriate password policies

Problem: 401 Unauthorized errors even with correct credentials
Solution: Check the application pool identity has proper permissions

Problem: Basic Authentication option still not visible
Solution: Run the following PowerShell command:
Install-WindowsFeature Web-Basic-Auth -IncludeManagementTools

For automation scenarios, use:

Import-Module WebAdministration
Set-WebConfigurationProperty -filter /system.webServer/security/authentication/basicAuthentication -name enabled -value true -PSPath IIS:\ -location 'YourSiteName'

Basic Authentication is one of the standard HTTP authentication methods that transmits credentials in base64-encoded format. While not the most secure option (credentials are sent in plaintext, though encoded), it remains widely used for legacy systems and internal applications where HTTPS is enforced.

If you don't see Basic Authentication in IIS Manager under Authentication modules, it's likely because the feature isn't installed. IIS 8 on Windows Server 2012 ships with many features disabled by default for security and performance reasons.

# PowerShell command to install Basic Authentication:
Add-WindowsFeature Web-Basic-Auth -IncludeManagementTools

Alternatively, you can use the GUI:

1. Open Server Manager
2. Navigate to "Manage" > "Add Roles and Features"
3. Select "Role-based or feature-based installation"
4. Choose your server
5. Under "Web Server (IIS)" > "Web Server" > "Security", check "Basic Authentication"
6. Complete the installation wizard

After installation:

1. Open IIS Manager
2. Select your site or application
3. Double-click "Authentication"
4. Right-click "Basic Authentication" > Enable
5. Click "Edit..." to specify default domain if needed

For programmatic control or deployment purposes, you can configure Basic Authentication in web.config:

<system.webServer>
  <security>
    <authentication>
      <basicAuthentication enabled="true" 
         realm="YourRealm"
         defaultLogonDomain="YOURDOMAIN" />
    </authentication>
  </security>
</system.webServer>

Always combine Basic Authentication with HTTPS (SSL/TLS) to protect credentials in transit. For better security, consider implementing:

• IP restrictions
• Request filtering
• Failed request tracing

If authentication fails, check:

• Application Pool identity permissions
• Windows user account permissions
• Firewall settings
• HTTP 401 error logs in Event Viewer

For detailed logging, enable Failed Request Tracing in IIS and examine the authentication sequence.