Hi FreeRADIUS: I've compiled/installed FreeRADIUS 3.2.8 on Ubuntu 24.04 (Linux 6.8.0 and OpenSSL 3.0.13), and it gives the attached "MS-CHAP2 Response is incorrect" error during inner tunnel negotiation in Phase 0 (PAC file creation) of EAP-FAST. Upgrading the Linux kernel to 6.16 and OpenSSL 3.0.16 gives the same result. Compiling the latest FreeRADIUS 3.2.x branch head (3.2.9 dev) as of a few days ago also gives the same result. Note that EAP-PEAP/MSCHAPV2 works fine (log also attached) on the identical supplicant / authenticator / authentication server platform. The supplicant is also on a Ubuntu 24.04 platform (OpenSSL 3.0.13), running the latest snapshot of wpa_supplicant, and TLS 1.3 has been confirmed working with EAP-PEAP when tls_max is set to 1.3 in FreeRADIUS on the authentication server. Supplicant version: dbland@NUC13-Linux2:~$ wpa_supplicant -v wpa_supplicant v2.12-devel-20251221-hostap_2_11-1307-g3ea5c0df5+ Copyright (c) 2003-2024, Jouni Malinen <j@w1.fi> and contributors dbland@NUC13-Linux2:~$ Supplicant EAP-FAST configuration: network={ ssid="asus6e_5" proto=RSN key_mgmt=WPA-EAP bgscan="simple:5:-70:60" eap=FAST identity="bob_loblaw" anonymous_identity="FAST-123456789012" password="password" phase1="fast_provisioning=1" phase2="auth=MSCHAPV2" pac_file="/home/dbland/certs_nuc13/bob_loblaw.pac" } Background: Recent Ubuntu versions have forcibly disabled TLS 1.0 and TLS 1.1, and EAP-FAST support with TLS 1.2 was first introduced in FreeRADIUS 3.2.8. However, the FreeRADIUS package version bundled with Ubuntu 24.04 is version 3.2.5, and version 3.2.7 with Ubuntu 25.10. This unfortunately leaves a gap in EAP-FAST support. Until a newer FreeRADIUS package is available on Ubuntu, compiling the 3.2.8 source seems to be the only option in order to support BOTH TLS 1.3 with EAP-PEAP and TLS 1.2 with EAP-FAST. Any further troubleshooting suggestions? From reading the mailing list archives, I've seen this EAP-FAST issue pop up a few times in the past on earlier 3.0.x versions, but with no resolution. Best regards, Dennis Bland