Common Issues with FreeRadius in Passwordless Implementations

This technical guide explains why FreeRADIUS remains central to passwordless EAP‑TLS deployments and details common production issues—such as unknown CA errors from missing roots or chain gaps, OCSP/CRL revocation behaviors, NAS IP/shared-secret mismatches in clients.conf, and CIAM/SQL attribute mapping problems—along with troubleshooting via `radiusd -X`, optional unlang policies, and best practices like automating cert issuance/renewals (SCEP/EST), auditing and rotating shared secrets, and centralizing identity.