User authentication functions are performed by external
LDAP, Kerberos, TACACS+, SAML, or RADIUS services (including support
for two-factor, token-based authentication mechanisms, such as one-time
password (OTP) authentication). To enable external authentication:
Create a server profile with settings for access to the
external authentication service.
Create an authentication profile that refers to the server
Specify client authentication in the portal and gateway configurations
and optionally specify the OS of the endpoint that will use these settings.