I've been following the FreeRadius Deployment guide http://deployingradius.com/documents/configuration/active_directory.html The following software is installed on a Centos 6 VM: - Samba 3.5.6, Freeradius 2.1.10, wpa_supplicant-0.7.3, gcc v4.4.4-13, openssl, winbind. I successfully performed basic configuration tests with the 'eapol_test' command for: - PAP, EAP, EAP-TLS, EAP-TTLS, EAP-MD5 & EAP-MSCHAPv5. I've created production certificates & successfully tested for the above protocols. Installed Kerberos 1.8.2 & tested that successfully. I've edited /etc/krb5.conf, as follows: [logging] default = FILE:/var/log/krb5libs.log kdc = FILE:/var/log/krb5kdc.log admin_server = FILE:/var/log/kadmind.log [libdefaults] default_realm = CAMPUS.ADS.UWE.AC.UK dns_lookup_realm = false dns_lookup_kdc = false ticket_lifetime = 24h renew_lifetime = 7d forwardable = true [realms] CAMPUS.ADS.UWE.AC.UK = { kdc = campus.ads.uwe.ac.uk admin_server = radius.uwe.ac.uk default_domain = CAMPUS.ADS.UWE.AC.UK } [domain_realm] .campus.ads.uwe.ac.uk = CAMPUS.ADS.UWE.AC.UK campus.ads.uwe.ac.uk = CAMPUS.ADS.UWE.AC.UK I've also edited /etc/samba/smb.conf (comments & blank lines excluded): [global] workgroup = CAMPUS server string = Samba Server Version %v log file = /var/log/samba/log.%m max log size = 50 security = ads passdb backend = tdbsam realm = campus.ads.uwe.ac.uk password server = campus.ads.uwe.ac.uk load printers = yes cups options = raw winbind separator = + idmap uid = 10000-20000 idmap gid = 10000-20000 winbind enum users = yes winbind enum groups = yes template homedir = /home/%D/%U template shell = /bin/rbash client use spnego = yes client ntlmv2 auth = yes encrypt passwords = yes winbind use default domain = yes restrict anonymous = 2 domain master = no local master = no preferred master = no os level = 0 [homes] comment = Home Directories browseable = no writable = yes [printers] comment = All Printers path = /var/spool/samba browseable = no guest ok = no writable = no printable = yes I then run 'net join -U USERNAME' and get: Unable to find a suitable server for domain CAMPUS Unable to find a suitable server for domain CAMPUS Running 'wbinfo -a USERNAME%PASSWORD' returns: plaintext password authentication failed Could not authenticate user USERNAME%PASSWORD with plaintext password challenge/response password authentication failed error code was NT_STATUS_NO_LOGON_SERVERS (0xc000005e) error messsage was: No logon servers Could not authenticate user USERNAME with challenge/response Can anyone tell me what I've done wrong? Thanks Martin.