I'm new to my organization, which primarily uses Windows, but we have a couple of CentOS 6.6 servers set up for Active Directory authentication. I managed to log in successfully, but no one remembers how this was originally configured, and I'm eager to learn more about it. I noticed realm/realmd are typically associated with AD integration, but they aren't installed on our CentOS machines. How can I investigate how these servers are connected to Active Directory? Any suggestions would be greatly appreciated as I'm not very familiar with Linux yet.
4 Answers
You can start by checking the `/etc/nsswitch.conf` file. This will show you how the Linux server is set up for authentication. It's likely that 'winbind' will be listed there, which is part of Samba.
Keep in mind that authentication and identity are two different things. This file will mostly tell you how identity is configured, likely through some LDAP mechanism. You’ll want to check `/etc/pam.d` too, especially 'system-auth', to see how authentication is managed.
Most likely, your system is utilizing Samba/winbind or possibly sssd. You can also check if there's a configuration file at `/etc/sssd/sssd.conf` which might provide more details on the setup.
As for realm/realmd, they're typically used for the initial AD integration on newer systems, but your CentOS might be employing older components like 'sss' or 'krb5'. You may want to dig into these old configurations to see how things were set up.
Does the presence of Kerberos-related binaries in `/etc/bin`, like klist, indicate that Kerberos is in use here, or are they just standard files that come with the system?
This setup might have been done according to the Red Hat Windows Integration Guide. Just a heads up, that guide might be outdated for CentOS 6, so if you plan to work on newer versions later, verify you're referring to the correct documentation.
Thanks, I'll take a look after lunch!