RADIUS and LDAP authentication are not intended for use with CLI in versions 2.3.X and lower, but this has recently changed for Radius in release 2.4.1.X. LDAP is still not supported.
Quote from the 2.4.1 Release Notes, page 8:
"CLI authentication using RADIUS credentials—Set up RADIUS authentication, and then provide RADIUS groups or individual users with administrator permissions".
Quote from the "Resolved Issues" of 188.8.131.52's Release notes:
[NPPCAS-5453] RADIUS authentication requests were being rejected.
You can perform a Direct Upgrade from any 2.3.X or 2.2.X version to 2.4.1.X if you please.
If your CAS is in version 2.1.X, you first need to upgrade to either 2.2 or 2.3, but CAS 184.108.40.206 can be directly upgraded to 2.4.1.