Configure Cisco ASA IKEv2 VPN

Okta provides the ability for organizations to manage authorization and access to on-premises applications and resources using the RADIUS protocol and the Okta RADIUS agent. With the Okta RADIUS Server Agent organizations can delegate authentication to Okta. This page describes how to configure Cisco ASA IKEV2 VPN to use EAP-TTLS and the Okta RADIUS Server Agent.

If you are using AnyConnect v4.4 and greater and ASA version 9.7.1 and greater consider using SAML.

Before you begin

Meet the following network connectivity requirements before you install the Okta RADIUS agent:

Source	Destination	Port/Protocol	Description
Okta RADIUS Agent	Okta Identity Cloud	TCP/443 HTTP	Configuration and authentication traffic.
Client Gateway	Okta RADIUS Agent	UDP/1812 RADIUS (Default, you can change this when you install and configure the RADIUS app)	RADIUS traffic between the gateway (client) and the RADIUS agent (server).

Limitations

Enroll only a single Okta Verify device. Adding more Okta Verify devices can cause undefined or unexpected behavior.

If you've migrated a RADIUS-configured org from Classic Engine and you configure the Okta Verify authenticator with the number challenge, the challenge may be presented to RADIUS users even though it's not supported. To prevent this, enable the Early Access feature Disable number matching challenge for RADIUS. See Enable self-service features.

Supported factors

The size of the challenge message can be too large for the RADIUS prompt if you let users enroll too many authenticators. Okta recommends that you enroll no more than eight authenticators at a given time.

Okta supports the following authenticators for RADIUS apps:

MFA Authenticator	Password Authentication Protocol (PAP)	Extensible Authentication Protocol - Generic Token Card (EAP-GTC)	Extensible Authentication Protocol - Tunneled Transport Layer Security (EAP-TTLS)*
Duo (Push, SMS, and Passcode only)	Supported	Supported	Duo passcode only.
Email	Supported	Supported	Supported when the string "EMAIL" is initially sent. Refer to associated note.
RADIUS doesn't support inline enrollment with Email. When using inline enrollment, either disable Email or specify Password reset in Email settings.
Google authenticator	Supported	Supported	Supported, as long as challenge is avoided. For example MFA only or "Password, passcode".
Okta Verify (TOTP and PUSH)	Supported (for one device only)	Supported (for one device only)	Supported (for one device only), as long as challenge is avoided. For example: MFA-only or "Password, MFA" for TOTP. Push can work with primary authentication with MFA as the push challenge is sent out-of-band.
Okta Verify (number challenge)	Not supported	Not supported	Not supported
Phone (SMS and Voice call)	Supported	Supported	Supported when the string "CALL" is sent. Refer to associated note.
YubiKey OTP	Supported	Supported	Supported - as long as challenge is avoided. For example MFA only or "Password, passcode".

* RADIUS supports three authentication methods:

Password + MFA: Primary authentication using password, then the user is prompted to select factors to complete the authentication.
MFA Only: Instead of password, users enter either a one-time passcode (OTP), or one of EMAIL, SMS, CALL, PUSH (case insensitive).
Password and Passcode: Password entered immediately followed by a passcode in a request.
Must be in the same request, for example: Abcd1234,879890" or "Abcd1234,SmS".

Protocols support the following authentication methods:

Protocol	Supports
PAP	Password and MFA, MFA, "Password and passcode".
EAP-TTLS	MFA only, "Password and passcode".
EAP-GTC	Password and MFA, MFA only, "Password and passcode".

Users must send the specified string EMAIL/SMS/CALL, which initially returns a failure. This results in the generation of an OTP provided using the specified method. The provided OTP can then be used for authentication.

EAP-TTLS doesn't support enrollment

Authentication will fail unexpectedly when EAP-TTLS is enabled, either Okta Verify or Phone are specified as the required enrollment policy, and the user isn't enrolled in that authenticator.

The U2F Security and Windows Hello MFA factors aren't compatible with RADIUS-enabled implementations. See Configuring RADIUS applications in Okta.

Passwordless authentication

RADIUS authentication uses passwords as the primary authentication mechanism. Traditional RADIUS authentication can't be performed with passwordless users. RADIUS can use other factors for authentication when the application setting property Okta performs primary authentication is cleared. See 2FA Only (Passwordless Mode) in RADIUS applications in Okta for addition detail.

For more information on passwordless authentication see Set up passwordless sign-in experience.

Typical workflow