<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Greetings!<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> Everyone seems to say that you can’t have a domain trust across two Kerberos realms (FreeIPA and Active Directory) if the hosts share the same DNS domain.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> Hadoop seems to do this just fine, though. I’m in the process of helping someone setup a trust between the Kerberos realms HADOOP.COMPANY.COM and COMPANY.COM and all of the servers use the company.com DNS domain. (see http://www.cloudera.com/documentation/archive/cdh/4-x/4-5-0/CDH4-Security-Guide/cdh4sg_topic_15.html)<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> This seems to be standard practice for setting up hadoop clusters. Why wouldn’t setting up a one-way trust so that FREEIPA.COMPANY.COM trusts COMPANY.COM (with all involved servers having the “company.com” DNS domain)? As I understand it, the Kerberos realm FreeIPA uses can be specified during the initial setup and it doesn’t have to match the domain.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>--David Alston<o:p></o:p></p></div></body></html>