Kerberos is dependent on A records in dns. The instance (as in principal/instance@REALM) should match the A record in dns. There is absolutely no Kerberos dependency on hostnames being fully qualified. I have all my devices named with short names and I have no issues with Kerberos ticketing. This seems to be an artificial requirement in FreeIPA that is wrong. <div class="gmail_quote">On Aug 8, 2014 8:54 AM, "Bruno Henrique Barbosa" <<a href="mailto:bruno-barbosa@prodesan.com.br">bruno-barbosa@prodesan.com.br</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div><div style="font-family:tahoma,new york,times,serif;font-size:12pt;color:#000000">Hello everyone, I'm running through an issue where an application needs its server's hostname to be in short name format, such as "server" and not "<a href="http://server.example.com" target="_blank">server.example.com</a>". When I started deploying FreeIPA in the very beginning of this year, I remember I couldn't install freeipa-client with a bare "ipa-client install", because of this: ____________ [root@server ~]# hostname server [root@server ~]# hostname -f <a href="http://server.example.com" target="_blank">server.example.com</a> [root@server ~]# ipa-client-install Discovery was successful! Hostname: <a href="http://server.example.com" target="_blank">server.example.com</a> Realm: <a href="http://EXAMPLE.COM" target="_blank">EXAMPLE.COM</a> DNS Domain: <a href="http://example.com" target="_blank">example.com</a> IPA Server: <a href="http://ipa01.example.com" target="_blank">ipa01.example.com</a> Base DN: dc=example,dc=com Continue to configure the system with these values? [no] yes User authorized to enroll computers: admin Synchronizing time with KDC... Unable to sync time with IPA NTP Server, assuming the time is in sync. Please check that port 123 UDP is opened. Password for <a href="mailto:admin@EXAMPLE.COM" target="_blank">admin@EXAMPLE.COM</a>: Joining realm failed: The hostname must be fully-qualified: server Installation failed. Rolling back changes. IPA client is not configured on this system. ________________ So, using the short name as hostname didn't work for install, I then make it like "ipa-client install --hostname=`hostname -f` --mkhomedir -N", and it installs and works like a charm, BUT it updates the machine's hostname to FQDN. What I tested and, at first, worked: after deploying and ipa-client installation with those parameters which work, renaming the machine back to a short name AT FIRST is not causing any problems. I can login with my ssh rules perfectly, but I don't find any IPA technical docs saying it will/won't work if I change the hostname back to short name and not FQDN. Searching for it, I found on RedHat guide: "The hostname of a system is critical for the correct operation of Kerberos and SSL. Both of these security mechanisms rely on the hostname to ensure that communication is occurring between the specified hosts." I've also found this message <a href="http://osdir.com/ml/freeipa-users/2012-03/msg00006.html" target="_blank">http://osdir.com/ml/freeipa-users/2012-03/msg00006.html</a> which seems to be related to my case, but what I need to know is: where does it state FQDN is a mandatory requirement in order to FreeIPA to work and/or is there anything else (a patch, update, whatever) to solve this issue, so I don't need to change my applications? Thank you and sorry for the wall of a text. PS: Enviroment is CentOS 6.5, in both IPA server and client. DNS is not the same server as IPA (it forwards to a Windows DC). RPMs: libipa_hbac-1.9.2-129.el6_5.4.x86_64 libipa_hbac-python-1.9.2-129.el6_5.4.x86_64 python-iniparse-0.3.1-2.1.el6.noarch ipa-pki-common-theme-9.0.3-7.el6.noarch ipa-pki-ca-theme-9.0.3-7.el6.noarch ipa-admintools-3.0.0-37.el6.x86_64 ipa-server-selinux-3.0.0-37.el6.x86_64 ipa-server-3.0.0-37.el6.x86_64 ipa-python-3.0.0-37.el6.x86_64 ipa-client-3.0.0-37.el6.x86_64 </div></div> -- Manage your subscription for the Freeipa-users mailing list: <a href="https://www.redhat.com/mailman/listinfo/freeipa-users" target="_blank">https://www.redhat.com/mailman/listinfo/freeipa-users</a> Go To <a href="http://freeipa.org" target="_blank">http://freeipa.org</a> for more info on the project </blockquote></div>