http://blogs.technet.com/dougl/archive/2009/06/12/communicator-automatic-configuration-and-split-brain-dns.aspxA lot has been written about the way that Microsoft Office Communicator uses DNS to automatically discover a registration point for a given SIP URI. I won’t repeat all of that here. But, I do want to emphasize one of the unique constraints that Communicatoren-USCommunityServer 2.1 SP1 (Build: 61025.2)http://blogs.technet.com/dougl/archive/2009/06/12/communicator-automatic-configuration-and-split-brain-dns.aspx#3255663Wed, 17 Jun 2009 05:39:53 GMTd5e57398-b9ef-4490-9955-07cbb4e4a80d:3255663JeffNye<p>Wow, people need to argue with you more. &nbsp;Nice post.</p>http://blogs.technet.com/dougl/archive/2009/06/12/communicator-automatic-configuration-and-split-brain-dns.aspx#3256166Thu, 18 Jun 2009 11:13:22 GMTd5e57398-b9ef-4490-9955-07cbb4e4a80d:3256166Manuel<p>Great explanation. &nbsp;Good work!</p> <p>Thank you for that.</p>http://blogs.technet.com/dougl/archive/2009/06/12/communicator-automatic-configuration-and-split-brain-dns.aspx#3267163Wed, 22 Jul 2009 20:20:54 GMTd5e57398-b9ef-4490-9955-07cbb4e4a80d:3267163Melissa Swofford<p>Thanks, Doug. &nbsp;We are seeing this at more and more sites and your blog provides an excellent reference for those with questions.</p>http://blogs.technet.com/dougl/archive/2009/06/12/communicator-automatic-configuration-and-split-brain-dns.aspx#3268814Tue, 28 Jul 2009 22:01:53 GMTd5e57398-b9ef-4490-9955-07cbb4e4a80d:3268814Mark Hickson<p>This is an AWESOME post! &nbsp;Great job and thank you!</p>http://blogs.technet.com/dougl/archive/2009/06/12/communicator-automatic-configuration-and-split-brain-dns.aspx#3292918Tue, 10 Nov 2009 19:24:45 GMTd5e57398-b9ef-4490-9955-07cbb4e4a80d:3292918Jim Raymond<p>I'm not that person, but trust me...don't argue with Doug. ;)</p> <p>Nice post, wish I had thought of this a year and a half ago when I was faced with adding the external zone internally.</p>