Configure Cisco ASA IKEV2 VPN to interoperate with Okta via RADIUS

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.

Topics

Before you begin

Before installing the Okta RADIUS Agent ensure that you have met these minimum requirements for network connectivity:

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, may be changed in RADIUS app install and configuration) RADIUS traffic between the gateway (client) and the RADIUS Agent (server)

Supported factors

The following MFA Factors are supported:

When integrating with Okta RADIUS, the maximum supported number of enrolled factors is dependent on the size of resulting challenge message. Okta recommends that no more than eight ( 8 ) be enrolled at one time.

MFA Factor Password Authentication Protocol
PAP		 Extensible Authentication Protocol - Generic Token Card
EAP-GTC		 Extensible Authentication Protocol - Tunneled Transport Layer Security
EAP-TTLS
Custom TOTP Authentication Supported Supported Supported
Duo(Push, SMS and Passcode only) Supported Not supported Not supported

Email

Supported

Supported

Not supported

Google Authenticator

Supported Supported Supported - as long as challenge is avoided.
For example MFA only or password, MFA.

Okta Verify (TOTP and PUSH)

Supported Supported Supported - as long as challenge is avoided.
For example:
MFA-only or password, MFA for TOTP.
Push can work with primary auth + MFA as the push challenge is sent out-of-band.

Okta Verify (number challenge)

Not supported

Not supported

Not supported

RSA Token

Supported

Supported

Supported

Security Question

Supported Supported Not supported
SMS authentication Supported Supported Not supported
Symantec VIP Supported Supported Supported

Voice Call

Supported Supported Not supported

YubiKey

Supported Supported Supported

EAP-TTLS does not support enrollment
Authentication will fail unexpectedly when EAP-TTLS is enabled, either Okta Verify or Phone are specified as required enrollment policy, and the user is not enrolled in that factor.

The U2F Security and Windows Hello MFA factors are not compatible with RADIUS-enabled implementations.
For additional information about the RADIUS apps refer to Configuring RADIUS applications in Okta.

Passwordless authentication
RADIUS authentication uses passwords as the primary authentication mechanism. Traditional RADIUS authentication cannot be performed with passwordless users. RADIUS can use other factors for authentication when the application setting property Okta performs primary authentication is unchecked. See2FA 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

Task

Description

Download the RADIUS agent
Install the Okta RADIUS Agent.
  • Install either the Windows or Linux RADIUS agents as appropriate for your environment.
Configure application
Configure gateway
Configure optional settings
Configure Windows VPN
Add root CA
Test

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