Sorry in advance for the most likely repeated question. After searching for a week, and still being stuck, it was time to ask the mailing list. I have a CentOS 6.4 machine that I'm trying to use SSSD/LDAP/KRB5 to authenticate with active directory. I can do ldapsearch commands with ldap, or ldaps (the ldap only works due to the machine account, using GSSAPI, otherwise, my domain doesn't support anonymous binding). I can kinit my username, and klist shows the host/hostname entries. OpenSSL doesn't complain about my certs. My only problem seems to be SSSD saying my ports are down. I get the same message for 389 and 636. Once it's marked as not working, the authentication clearly fails (first login, no cache to fall back on). I can telnet to the ports from the centos machine. I can telnet (well, kitty in telnet mode) to them from my windows workstation. Any ideas? Installed versions: sssd-1.9.2-82.4.el6_4.x86_64 sssd-client-1.9.2-82.4.el6_4.x86_64 openldap-2.4.23-32.el6_4.x86_64 openldap-clients-2.4.23-32.el6_4.x86_64 nss-3.14.0.0-12.el6.x86_64 krb5-workstation-1.10.3-10.el6_4.1.x86_64 pam-1.1.1-13.el6.x86_64 kstart-4.1-2.el6.x86_64 msktutil-0.4.2-1.el6.x86_64 My ldapsearch commands, ldapsearch -H ldaps://server.fqdn:636/ -Y GSSAPI -N -b "dc=example,dc=corp" "(&(objectClass=user)(sAMAccountName=username))" ldapsearch -H ldaps://server.fqdn:636/ -x -b '' -s base supportedSASLMechanisms Both of those work, and can work over non-tls ldap. openssl s_client -connect server.fqdn:636 -CAfile /etc/openldap/certs/adpubkeycerts.pem That command works fine. (Fri Apr 5 20:43:49 2013) [[sssd[ldap_child[1532]]]] [sss_child_krb5_trace_cb] (0x4000): [1532] 1365219829.627008: Received error from KDC: -1765328378/Client not found in Kerberos database (Fri Apr 5 20:43:49 2013) [sssd[be[domain.corp]]] [sdap_get_tgt_recv] (0x0400): Child responded: 14 [Client not found in Kerberos database], expired on [0] (Fri Apr 5 20:43:49 2013) [sssd[be[domain.corp]]] [sdap_kinit_done] (0x0100): Could not get TGT: 14 [Bad address] (Fri Apr 5 20:43:49 2013) [sssd[be[domain.corp]]] [sdap_cli_kinit_done] (0x0400): Cannot get a TGT: ret [5] result [4] I'm assuming those log entries are my problem. Or not, I fixed those by adding this to sssd.conf, which doesn't seem like it should be needed, as I would think it'd pick it up from /etc/krb5.keytab: ldap_sasl_authid = server$@fqdn Well, at least that's progress, still can't login though with an AD account. Hopefully that's just a matter of fixing these: (Fri Apr 5 22:11:34 2013) [sssd[be[domain.corp]]] [krb5_auth_send] (0x0100): No ccache file for user [ADUser] found. (Fri Apr 5 22:11:34 2013) [sssd[be[domain.corp]]] [krb5_auth_send] (0x4000): Ccache_file is [not set] and is not active and TGT is not valid. Any help would be appreciated, Thanks, Chris