Types of Authentication Modes Supported by IIS

Internet Information Services (IIS) supports several authentication modes to control access to websites and applications hosted on the server. The main authentication modes supported by IIS include:

1. Anonymous Authentication: This mode allows users to access the website without providing any credentials. The server uses a built-in account to authenticate the user.
2. Basic Authentication: Users are required to provide a username and password, which are sent in plain text over the network. This method is not secure and should be used with caution.
3. Windows Authentication: This mode validates user credentials against the Windows user database. It provides a secure way to authenticate users using NTLM or Kerberos protocols.
4. Digest Authentication: Similar to Basic Authentication, users are required to provide a username and password, but the credentials are hashed before sending them over the network, providing better security than Basic Authentication.
5. Forms Authentication: This mode allows developers to authenticate users using custom login forms. Users provide their credentials through a form, and the server validates them against a user database.

Each authentication mode has its own advantages and disadvantages in terms of security, ease of implementation, and compatibility with different client browsers. Administrators should choose the appropriate authentication mode based on the specific security requirements of their websites or applications.