Hello, I've a Linux Ubuntu 18.04 server with Freeradius 3.0.16 on x86_64 virtual machine. Freeradius is used only to provide Android devices authentication (EAP-TLS); the authentication works. The WiFi network was installed by my client: it is a geographical distributed WiFi with a controller and 10 access points. Sometimes, when one smartphone moves out of WiFi network area and then come back, the connection to WiFi fails. I can reconnect only after a WiFi off / on from Android network settings. I want to investigate this behaviour; I've found these recurring errors inside last month log files: ERROR: rlm_eap (EAP): No EAP session matching state 0x3d4e1475385119b8 ERROR: TLS Alert write:fatal:protocol version ERROR: TLS Alert read : fatal:unknown CA ERROR: (658258) eap_tls: ERROR: TLS Alert read : fatal : internal error ERROR: (644636) eap_tls: ERROR: TLS Alert read : fatal:bad certificate ERROR: (639156) eap: ERROR: rlm_eap (EAP): Aborting! More than 50 roundtrips made in session with state 0xfd858905cfb18490 ERROR: (367333) eap_tls: ERROR: TLS Alert write:fatal:protocol version Could you please suggest a debug checklist / debug process to help me understand why this behaviour happen? Thanks. Dario Barbon