# Multi-factor authentication

Parallels RAS allows you to use multi-factor authentication for access control. When multi-factor authentication is used, users will have to authenticate through two successive stages to get the application list. While the first level will always use native authentication (Active Directory / LDAP), the second level can use one of the following solutions:

* [RADIUS](https://docs.parallels.com/landing/ras-admin-guide/parallels-ras-21-administrators-guide/connection-and-authentication-settings/multi-factor-authentication/using-radius)
  * Azure MFA (RADIUS)
  * Duo (RADIUS)
  * FortiAuthenticator (RADIUS)
  * TekRADIUS
  * RADIUS
* [TOTP](https://docs.parallels.com/landing/ras-admin-guide/parallels-ras-21-administrators-guide/connection-and-authentication-settings/multi-factor-authentication/using-totp)
  * Google Authenticator
  * Microsoft Authenticator
  * TOTP (Time-based one-time password)
* [Email OTP](https://docs.parallels.com/landing/ras-admin-guide/parallels-ras-21-administrators-guide/connection-and-authentication-settings/multi-factor-authentication/configuring-email-otp)
* [Deepnet](https://docs.parallels.com/landing/ras-admin-guide/parallels-ras-21-administrators-guide/connection-and-authentication-settings/multi-factor-authentication/using-deepnet-dualshield)
* [SafeNet](https://docs.parallels.com/landing/ras-admin-guide/parallels-ras-21-administrators-guide/connection-and-authentication-settings/multi-factor-authentication/using-safenet)

Multi-factor authentication is more secure because instead of using a standard user name and password, it uses a static user name and a one-time password generated by a token.

Learn how to add an MFA provider in the [**Adding an MFA provider**](https://docs.parallels.com/landing/ras-admin-guide/parallels-ras-21-administrators-guide/connection-and-authentication-settings/multi-factor-authentication/adding-an-mfa-provider) section.

See also [**Configuring MFA rules**](https://docs.parallels.com/landing/ras-admin-guide/parallels-ras-21-administrators-guide/connection-and-authentication-settings/multi-factor-authentication/configuring-mfa-rules).