Site 1: 2 (load-balanced) internet facing CAS, 2 MBX. Outlook Anywhere enabled and working Site 2: CAS/MBX on the same box. Do I have to anable Outlook Anyhere on this box? If yes, what should be the external host name? The same as the CASs' in Site 1?

Hi If you want it to be "connectable" if anything happens to the other yes, configure it with an other additional name, this name needs to be included in the certificate and the necessary ports needs to be opened in the FW (443). Why not add one more CAS server in your Site 1 and create a casarray of them so you don't have a SPOF?Jonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog

No you don't. Outlook Anywhere connections are not proxied, thus thie CAS servers in you internet facing site will just connect directly to the mailbox in the non-internet facing site. You can enable it if you want to, but it will not make any difference. If you do however enable it, make sure that it does match the name of the internet facing sites, your your clients (outlook 2007+) will get wrong autodiscover values and stop working :-) Casper Pieterse, Principle Consultant - UC, Dimension Data South Africa, Microsoft Certified Master: Exchange 2007

So it will not work they way I thought? Ex. Failing over everything to Site 2, the CAS have an additional address like owa2.domain.com and the webmail can be reached that way instead of owa.domain.com (which is offline) Or how should this be handled?Jonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog | Follow me on twitter: jonand82

Found a good article about this http://technet.microsoft.com/en-us/library/bb310763.aspxJonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog | Follow me on twitter: jonand82

Hi, For this issue, you can get the relevant information from the below link: http://www.msexchange.org/articles_tutorials/exchange-server-2010/high-availability-recovery/designing-site-resilient-exchange-2010-solution-part1.html Thanks AllenAllen Song