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.

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 - as long as challenge is avoided. For example MFA only or "Password, passcode".
Duo(Push, SMS and Passcode only)	Supported	Supported	Duo passcode only.
Email	Supported	Supported	Supported when string "EMAIL" is initially sent. See associated note.
Google Authenticator	Supported	Supported	Supported - as long as challenge is avoided. For example MFA only or "Password, passcode".
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 authentication with MFA as the push challenge is sent out-of-band.
Okta Verify (number challenge)	Not supported	Not supported	Not supported
RSA Token/ On-prem MFA	Supported	Supported	Supported - as long as challenge is avoided. For example MFA only or "Password, passcode".
Security Question	Supported (Password and MFA only)	Supported (Password + MFA only).	Not supported
SMS authentication	Supported	Supported	Supported when string "SMS" is sent. See associated note.
Symantec VIP	Supported	Supported	Supported - as long as challenge is avoided. For example MFA only or "Password, passcode".
Voice Call	Supported	Supported	Supported when string "CALL" is sent. See associated note.
YubiKey	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 user is prompted to select factors to complete the authentication.
MFA Only: Instead of password, user enter either One Time Passcode, or one of “EMAIL”, “SMS”, “CALL”, “PUSH” (case insensitive).
Password,Passcode: Password entered immediately followed by passcode in a request.
Must be in the same request, for example: Abcd1234,879890” or “Abcd1234,SmS”.

The following authentication methods are supported by protocol:

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".

Must send the specified the string “EMAIL/SMS/CALL”, which will initially return a failure, but will result in the generation of an One Time Passcode(OTP) provided using the specified method. The provided OTP can then be used for authentication.

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	Download the Okta RADIUS Agent from the Settings > Downloads page your in Okta org. Note that there are both Windows and Linux agents. For throughput, availability and other considerations, see Okta RADIUS Server Agent Deployment Best Practices.
Install the Okta RADIUS Agent.	Install either the Windows or Linux RADIUS agents as appropriate for your environment.
Configure application	In your Okta org, configure the Cisco ASA - RADIUS application.
Configure gateway	Using the Cisco ASDM console, configure the configure Cisco ASA VPN to use the Okta RADIUS App.
Configure optional settings	Cisco ASA supports two optional settings: Client IP Reporting and Groups response. Configure optional settings
Configure Windows VPN	On the Windows client configure the Windows VPN.
Add root CA	Windows clients can avoid man in the middle attacks by adding trusted CA certificates. On the Windows client install a trusted root CA certificate.
Test	Test the new integration.

Configure Cisco ASA IKEV2 VPN to interoperate with Okta via RADIUS

Topics

Before you begin

Supported factors

Typical workflow

Related topics