Hi list, I successfully installed and configured our FreeRADIUS server with the following results: EAP-TLS => works on Windows 10, iOS 13, macOS 10.15 (Catalina) EAP-TTLS + PAP (LDAP auth) => works on Windows 10, iOS 13, macOS 10.15 EAP-TTLS + PAP (LDAP auth) + client cert => NOT works on Windows 10, but works on iOS 13, macOS 10.15 The last option with Windows 10 produces the following error logs: (185) eap_ttls: ERROR: TLS Alert write:fatal:handshake failure tls: TLS_accept: Error in error (185) eap_ttls: ERROR: Failed in __FUNCTION__ (SSL_read): error:1417C0C7:SSL routines:tls_process_client_certificate:peer did not return a certificate (185) eap_ttls: ERROR: System call (I/O) error (-1) (185) eap_ttls: ERROR: TLS receive handshake failed during operation (185) eap_ttls: ERROR: [eaptls process] = fail (185) eap: ERROR: Failed continuing EAP TTLS (21) session. EAP sub-module failed Windows 10 logs: Wireless 802.1x authentication failed. Error: 0x80420015 EAP Reason: 0x80420015 EAP Root cause String: EAP Error: 0x80420015 I tried nearly all combinations in the Windows 10 configuration interface, but it never sends the client_cert with EAP-TTLS (the same settings with EAP-TLS work). When trying to connect to Wi-FI the Windows 10 interface looks like: Choose a certificate: <correctly pre-selected certificate> User name: <my username entered manually> but after clicking to connect the server never receives the selected certificate ... Is the optional "client cert" in EAP-TTLS supported on Windows 10? Any ideas to get it working? Thanks, JM