Hello, I was stuck for a bit on this error message before finding the solution, so I thought I'd share and get it into the list archives for future reference. Context: Trying to get WindowsXP 802.1X supplicants to be authenticated on a FreeRADIUS server. After a successful TLS handshake, the rlm_eap_tls: Received unexpected tunneled data after successful handshake message would appear and abort the process. The solution is in http://www.freeradius.org/doc/EAPTLS.pdf - the client and server certificates must contain an Enhanced Key Usage. Look for "-extensions" in the generation script, and for the "OpenSSL extensions file" section. Taking this into account and regenerating the client & server certificates worked for me. I hope it helps, -Waba.