Hello

Running Exchange 2013 ru8. I have 4 CAS and 4 mailbox servers, the servers are not multi role. I want to change the authentication on one particular CAS servers /ECP virtual directory, however I know changing the authentication on /ECP will also effect /OWA, as the two virtual directories follow the same authentication. Because of this I am going to create a new website on one of the CAS servers, then create a new /ECP virtual dir under the new website. My question is, if I create a new website on one of the CAS servers, do I also have to create a new website on one of the backend mailbox servers, and create a /ECP virtual dir on the backend mailbox server ?  I know I need to create an additional A record in DNS for the newly created website, example "admin.mydomain.com/ECP" however how does the CAS sever that "Admin.mydomain.com" resolves to knows which mailbox server to proxy the request to? Again I only want to do this on one mailbox server and one CAS server

Thank you

Why not just change the authentication on one of the servers and use it only for ECP, while continuing to direct OWA to the other three?

Hi Ed

That is certainly an option. This would mean I wouldn't have to go through the hassle of having to create an additional website. However if this turns out to not be an option for our environment, do also need to create a new website on the backend mailbox server as well as the CAS server? Also how does the CAS server know which mailbox server to proxy the request to? are host files used on the CAS server to do this?

Thank you 

I don't believe you have to do anything to the mailbox server.

Hi Ed

I believe you have to change the authentication on the mailbox server so it matches the authentication on the CAS server for /ECP virtual directory

Hi,

From your description, I would like to clarify the following thing:

In your case, if you want to set the different authentication for ECP and OWA, you just need to create a new virtual directory for ECP with the authentication that you want, and then assign a new IP and new DNS name.

Hope my clarification can be helpful to you.

Best regards,

Official blog post : http://blogs.technet.com/b/exchange/archive/2015/02/11/configuring-multiple-owa-ecp-virtual-directories-on-the-exchange-2013-client-access-server-role.aspx