Which four authentication types can a Citrix Administrator use for Citrix ADC authentication, authorization, and auditing (AAA) multi-factor authentication? (Choose four.)

Jovan I.Mar 12, 2026

The correct answers are C, D, F, and G, meaning RADIUS, TACACS+, OAuth, and LDAP. In a Citrix ADC AAA nFactor or classic MFA chain, those four are native authentication action types you can actually bind to a policy and drop into a login schema flow. LDAP and RADIUS are the workhorses you see in almost every deployment, TACACS+ covers the network-device-access auditing cases, and OAuth plugs into identity providers through the authorization code flow so you get token-based federation without leaving the ADC policy engine. ADFS is not an authentication type on the ADC, it is an identity provider you reach through SAML or OAuth, so it gets its own action type by proxy, not directly. SMS is a delivery channel for OTP values, not a protocol the ADC authenticates against, and FIDO2 is not a supported authentication action type in the 1Y0-231 scope. If you see a lab question asking you to configure nFactor with two factors, your go-to combination from this list is LDAP as factor one and RADIUS as factor two, bind them to the right policy labels, and make sure your vServer has the AAA type set before you start troubleshooting why tokens are not reaching the backend.

Samuel O.Mar 22, 2026

RADIUS, TACACS+, OAuth, and LDAP, but why do you think ADFS didn't make the cut here?

Brenda K.Mar 16, 2026

Clock check first: this is a four-answer multi-select, so do not freeze up trying to find a single best option. Flag it if you need to but I would not, because the answer set here is actually pretty clean once you think about what ADC AAA nFactor actually supports. I am going with B, C, G, and E. SMS one-time passcode is a classic second factor the ADC nFactor flow handles natively, RADIUS is the backbone of half the MFA deployments I have seen in real environments, LDAP is your primary identity source in virtually every AAA config, and FIDO2 is the one people sleep on but Citrix added hardware token and passkey support precisely to get FIDO2 into the nFactor chain. ADFS is a Microsoft federation service, not an ADC authentication type you configure directly inside the AAA virtual server, and TACACS+ is a device-administration protocol that belongs to network gear management, not end-user MFA. OAuth is an authorization framework and while ADC has OAuth support it is not listed as a discrete AAA authentication type in the same category as the others on this exam blueprint. The trap on this question is crossing out FIDO2 because it feels newer or less familiar, but Citrix has been explicit in their documentation about FIDO2 device authentication as a supported nFactor method and the 1Y0-231 blueprint reflects that. Do not let unfamiliarity cost you a point here. Lock in B, C, E, G and move on, this should not eat more than 45 seconds of your clock.