Hi,
In my current environment I have 2 Exchange 2010 servers with DAG no CAS NLB. I installed Exchange 2013 with 2 CAS with WNLB and 2 Mailboxes with DAG. The main requirement is to configure Single name space to access in between Exchange 2010 and Exchange 2013. On Exchange 2010 DAG there is a URL using is owa.domain.com and I also configured in Exchange 2013 all the virtual directories with this name owa.domain.com but having an issue that when I open explorer and use the owa.domain.com URL the user on Exchange 2013 gets their mailbox but user on Exchange 2010 gets error HTTP 403 blank page.
I observed that in Exchange Organization settings CAS settings one server OWA, ECP etc shows their internal external URL but the other server unable to open the OWA, ECP URL and give error message that "An IIS directory entry couldn't be created. The error message is Access is denied. HResult = -2147024891"
Please guide how to resolve this issue and use the same name URL in Exchange 2010 and Exchange 2013
Thanks,