Hi,

(Warning: It’s been a looong day, and upon rereading, the below may not be entirely coherent. I’ll gladly clarify in the morning where needed)

We’ve been struggling for several months with getting our Linux (a mix of CentOS 7 and RHEL 7.1) servers AD integrated. We have a Win2012R2 domain with two sites, and several cross-forest, one-way trusts, and at the moment we are mostly (see below) able to authenticate with accounts local to our domain. We currently have two problems (that we know of):

* After a few days, it is no longer possible to log in with a domain account. Restarting sssd mostly works, and if not, performing a domain join again does. What we’ve seen is that this seems to change the KVNO field of kinit -k, and we’ve seen an error message (which I can’t find again at the moment, sorry) indicating that this is a problem. Oddly enough, on some of the servers which we still can log on to, the KVNO can be different from the one which we just “fixed”.  The KVNO seems to always be either 2 or 5, switching when we “fix” a server.

* Authenticating with an account from a trusted domain never works. I can ping domain controllers from the other domain, I can telnet all the AD ports I can think of (significantly, 389 and 88), and there’s no real error message shown anywhere. Right now /var/log/secure complains about unknown users, and journalctl says “Unspecified GSS failure.  Minor code may provide more information (Server not found in Kerberos database)”. I can resolve both A and PTR records, both on local and remote domains.

I’m at a loss on how to continue with the troubleshooting. People are starting to mumble about requesting local accounts on all machines. Tonight, I tried throwing PBIS Open (previously Likewise) on a machine, and it just worked. I’d like to avoid PBIS, though, since it is a bit more opaque about how it works, and we’d probably end up having to pay to get the features we could get from sssd in a (mostly) more understandable and clean packaging. But this would at least seem to indicate that the issue is with our configuration, rather than some infrastructural problem?

Here’s the configuration files:

/etc/krb5.conf:

    [logging]

     default = FILE:/var/log/krb5libs.log

     kdc = FILE:/var/log/krb5kdc.log

     admin_server = FILE:/var/log/kadmind.log

[libdefaults]

     default_realm = AD.MAIN-DOMAIN.COM

     dns_lookup_realm = true

     dns_lookup_kdc = true

     ticket_lifetime = 24h

     renew_lifetime = 7d

forwardable = true

    [realms]

    [domain_realm]

/etc/sssd/sssd.conf

    [sssd]

    services = nss, pam, ssh, autofs

    config_file_version = 2

    domains = AD.MAIN-DOMAIN.COM

    [nss]

    override_homedir = /home/%d/%u

    override_shell = /bin/bash

    [domain/AD.MAIN-DOMAIN.COM]

    id_provider = ad

    use_fully_qualified_names = TRUE

    krb5_renew_interval = 1h

I tried replacing the krb5.conf file with the one generated by PBIS, but that didn’t help, unfortunately.

Any ideas for things to try would be greatly appreciated!

Best regards,

Carl