I have confused about autodiscover flow in Exchange 2013 / 2010 coexistence scenario. all the technet and other blogs says that Exchange 2013 will proxy the autodiscover request to the right site and server. now, we have 2 Exchange 2010 CAS, 2 Exchange 2010 Mailbox Server, and newly 2 created Exchange 2013 CAS&Mailbox Server.
All CAS servers AutoDiscoverSiteScope's are same except 2010 Disaster CAS server.
2010 CAS servers AutoDiscoverServiceInternalUri : https://legacy.domain.com/Autodiscover/autodiscover.xml
2013 Server AutoDiscoverServiceInternalUri: https://mail.domain.com/Autodiscover/autodiscover.xml
and we have a srv record of _autodiscover is pointing to mail.domain.com
we have split dns for our external domain: domain.com and internal dns record of legacy.domain.com is pointing to Exchange 2010 CAS Server VIP, mail.domain.com is pointing to Exchange 2013 CAS Servers VIP
when testing autodiscover connection on an exchange 2010 account is says "Attempting to https://legacy.domain.com/Autodiscover/autodiscover.xml found through SCP" and it success.
when testing autodiscover connection on an exchange 2013 account it is trying firstly "https://legacy.domain.com/Autodiscover/autodiscover.xml" because found through SCP after that it redirects with HTTP 302 to URL "https://mail.domain.com/Autodiscover/autodiscover.xml" and it success.
so this makes sense because Autodiscover query getting firstly "older created SCP" in Active Directory. but in this situation Exchange 2010 redirects connection to 2013 instead of Exchange 2013. is this OK for all exchange webservice? and for which situation Technet and all other blogs tells that Exchange 2013 proxying connection to 2010 Server of Exchange 2010 mailboxes, if 2010 and 2013 server in same site and 2013 server installed later. or have we missing something other?