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Hi folks,<br />
<br />
I'm wondering how to make the following a nice HA solution:<br />
<br />
- 2 Datacenters on different locations <br />
- On each DC there is a complete Exchange 2013 Infrastructure with dedicated ClientAccess Servers and dedicated Mailbox Servers with DAG<br />
<br />
How to make CAS HA in case of DC blackout?<br />
<br />
1st idea:<br />
<br />
- DNS Round Robin to client access server (con in case everything's fine = 50% of the client requests may contact the wrong CAS first, con in case of failover = client requests won't be answered if contacting failed server, 20 seconds timeout then retry other IP)<br />
<br />
How do you recommend make CAS an reliable deployment? <br />
<br />
Regards and tia<br />
Marcel
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Hi folks,

I'm wondering how to make the following a nice HA solution:

- 2 Datacenters on different locations 
- On each DC there is a complete Exchange 2013 Infrastructure with dedicated ClientAccess Servers and dedicated Mailbox Servers with DAG

How to make CAS HA in case of DC blackout?

1st idea:

- DNS Round Robin to client access server (con in case everything's fine = 50% of the client requests may contact the wrong CAS first, con in case of failover = client requests won't be answered if contacting failed server, 20 seconds timeout then retry other IP)

How do you recommend make CAS an reliable deployment? 

Regards and tia
Marcel

Exchange 2013 Client Access HA via two-datacenters

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.

Exchange

Within Internet message handling services (MHS), a message transfer agent or mail transfer agent (MTA) or mail relay is software that transfers electronic mail messages from one computer to another using a client–server application architecture. A MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol (SMTP). The terms mail server, mail exchanger, and MX host may also refer to a computer performing the MTA function. The Domain Name System (DNS) associates a mail server to a domain with mail exchanger (MX) resource records containing the domain name of a host providing MTA services.