Good morning, all!

I'm finalizing a design and starting production installations for a new Exchange 2013 SP1 infrastructure in our company.  I want to know if I can use two ETS servers, one in each datacenter, and cross-connect them to the CAS/Mailbox servers in the opposite datacenter.  It would look something like this:

The orange connections are the ones I would add.  Would this be a supported configuration for Exchange?  Might there be complications to be aware of prior to deploying this configuration?

Thanks to all for looking!

Gregg

So in this scenario, the Mailbox Server in DC1 would be sending all its messages out to the DC2 Edge and vice versa? That could work, but I would be concerned about any WAN failure since the Edge server would be subscribed to a AD site across a WAN link.

Hello, Andy!

Thanks for looking at this with me.  Apologies for the drawing; it may not be clear what I'm trying to achieve.

Each CAS/MB server would be using both ETS servers.  I'd imagine I could set a preference, number of hops, for instance.  The server in DC1 would be primary, but still send & receive mail through both ETS servers.  The secondary server in DC2 would likewise send & receive through both ETS servers, but would primarily use the ETS server in DC2.

This way, if the ETS server goes south for some reason we can still have mail flowing.  

Thanks!

Gregg

Ok, the problem there is that an Edge Server cant be subscribed to more than one AD site if I understand what you are proposing correctly. I assume there are 2 AD sites here.

Again, my apologies for missing a vital piece of information.  These are not two different AD sites - this is one AD.  

Thanks!

Gregg

Again, my apologies for missing a vital piece of information.  These are not two different AD sites - this is one AD.  

Thanks!

Gregg

Ok, so you have one AD site that stretches across 2 datacenters? Im not talking about the AD forest, but the logical AD sites

Correct, just one site over two DCs.  The second is a lights-out auxiliary datacenter.

Gregg

Correct, just one site over two DCs.  The second is a lights-out auxiliary datacenter.

Gregg

In that case, you can subscribe both Edge Servers to the same AD site of course ( and to the mailbox servers in that AD site), but outbound, the Edge Servers will be all configured to use the same send connector. In other words, the Edge Servers will be load balanced so you can not prioritize one Edge for one site and another Edge for the other site.

Hi,

Agreed with Andy, we can configure Load Balance for Edge server in your environment.

Generally, you can install more than one Edge Transport server in the perimeter network. Deploying more than one Edge Transport server provides redundancy and failover capabilities for your inbound message flow. You can load balance the SMTP traffic to your organization among Edge Transport servers by defining more than one MX record with the same priority value for your mail domain. You can achieve consistency in the configuration among multiple Edge Transport servers by using cloned configuration scripts.

For more information about the Edge Transport server, please refer to:

https://technet.microsoft.com/en-us/library/bb124701(v=exchg.150).aspx

Regards,