Hi,
We have 4 AD Sites,
Site A has the ExternalOWA CAS servers for the Whole Org and Site B has the majority (not all) mailboxes with its own CAS servers.
We installed Exchange 2010 back in SP1 before the CrossSiteRedirectType settings was introduced with SP2. Up until now we have not had any problems with the proxying between the external cas over to the other ones on other sites.
We have setup some new CAS Servers in Site C which will soon have majority of the mailboxes but when loggin onto OWA with a user who has a mailbox in Site C it is trying to redirect to the internal cas url on the Site C Cas which obviously isn't going to work from the outside. I then found out about this CrossSite setting and have set this to Silent on both of the External facing CAS servers, this got me a bit further in that it doesn't appear to be redirecting and maintains the external URL but nothing loads - I get HTTP 500 - most likely causes:
the website is under maintenance or the website has a programming error.
This has also broken OWA internally for those users on site C too.
On the new Servers in site C I have put the same External URL on the owa directory as the external facing ones as that was part of the config. Is this correct?
Many Thanks for any help..