Background: We are running a 2 node Exchange 2003 SP2 cluster on Windows Server 2003 SP2 (BE), with a single 2003 FE. All Domain Controllers are Server 2003 SP2, with 1 Windows 2008 DC in a remote location. I had a class in Exchange 2007, but it was entirely focused on a new install of Exchange 2007, not a coexistance with a 2003 environment. I have 2 Windows 2008 R2 servers built for our Exchange 2007 implementation. We are in native mode, and have already run the setup /preparelegacyexchangepermissions, setup /prepareschema, setup /preparead, and setup /preparedomain. OU and all groups were created in AD and schema has been replicated to all DC's. We are planning to install CAS on 1 of the 2008 R2 servers, and the mailbox and hub transport roles on the other 2008 R2 server. We are using an Ironport instead of an Edge Transport or ISA server. So, I have a few questions. Some stupid, other not so dumb (or dumber, I don't care, just want to get this right).
First, we attempted to install CAS, but when we did, our existing OWA ceased to function amoungst some other problems. Once we uninstalled CAS and corrected the other issues (not sure if they were related or not), our OWA site was functional again. We thought that we could install CAS and configure it, before installing our certificate and changing the VIP to point to it. So our first question. Do we have to remove Exchange 2003 from our FE before installing CAS? When I installing CAS, do I have to install Hub Transport on the CAS server as well for routing? Our mailbox/hub transport will not be up and running for a while yet. We want to get CAS and OWA functional first before proceeding, and I have read in several sites that CAS and Hub Transport needed to be installed. Please, I already know that there is a specific sequence to install and that CAS and Hub Transport need to be installed before the mailbox role, but many others seem to be installing CAS and Hub together?? Second, I have read that you CANNOT run a 2003 FE when you install CAS (atkjedi response in Q_23786098), but in another response, (endital1097 responds in Q_24625550), that you can have them run simultaneously. Others merely mention, that all you have to do is a URL redirect to the /exchange virtual folder. Can someone clarify this and if possible, provide a link to step-by-by step instructions for installing CAS. Microsoft's documentation is horrible to say the least. And every time I look for assistance, the story changes.