Hello,
I am
currently designing the new Excahnge 2013 environment that I am looking to deploy by the end of the month. And I have come up with two designs on what could be deployed. The first being an active/passive design with a single namespace across two sites.
One site being the primary site and the other being the secondary DR site in a single DAG. Now this is a common design and similar setups are documented in detail online on many blogs and such.
Where my trouble is with the second design I have come up with which is an active/active model using a multi namespace across the same two sites utilizing two DAGs. The idea here being the first site is the corporate head office which would only contain those users. While the second site would contain everyone else not based out of the head office. The goal being to cut out internal users from connecting all of the way into the primary site when they are external to it.
Now the way in which the network is setup between the two sites. Accessing the internet from the primary site requires you to go through the secondary. So for the second design my idea would be for external Outlook, OWA and ActiveSync connections would connect into the secondary site for it to then proxy over to the primary. Now I am used to how Excahnge 2010 did its proxying and if the ExternalUrl property was blank is knew to proxy to the other site. Is that still the case with Excahnge 2013 or it does not care at all and I can just populate both the internal/external url properties for all of the CAS servers at the primary site?
Now assuming I do populate both the internal/external url property in Excahnge 2013 for the primary site. And for this example I am going to use mail01.domainname.com for the primary site and mail02.domainname.com for the second. To get Outlook, OWA and ActiveSync to connect for users of the primary site externally would it be as simple as having that external internet DNS entry for mail01.domainname.com point to the same IP as mail02.domainname.com would be? With mail02.domainname.com pointing to a externally accessible load balancer for the second site.
Now applying the above logic and assuming as long as you hit a CAS server. And it will find your mailbox for you does that mean I can could also use the same namespace in both locations for say OWA and ActiveSync? So the idea being we want to keep using webmail.domainname.com for OWA access. So if I set that URL for both the primary and secondary site as long as I hit a CAS server in the secondary site. It will be able to connect over to the mailbox in the primary site for OWA?
Nicholas