Hi all,

I will have 2 CAS servers in main site and one in DR. Also will have two MBX servers in main site and one in DR. MBX servers will be configured in DAG and the two CAS servers in main will be configured in Windows NLB. The current exchange 2007 infrastructure consists from two CAS\HUB\MBX servers configured with Neverfail software for high availability solution. When I configure windows NLB between the two new exchange 2013 CAS servers in main, I need to put the exchange hostname i.e. webmail.domain.com as the NLB cluster hostname but this will break exchange 2007 and clients connectivity, right? what is the best practice?

Consider combining the CAS and Mailbox roles onto single servers and using a hardware or virtual load balancer instead.  Kemp Technologies makes a very nice product.

What does Neverfail offer you that's not already built into Exchange 2013?

If you want the best user experience, after getting everything built, switch the OWA URL over to Exchange 2013 and use a legacy URL for Exchange 2007 redirect.

Hi,

Have you checked the suggestion Ed provided?

Is there any update with your issue?

Best regards,

Our customer will user Windows NLB between CAS servers and have each role installed on different servers. For mailbox role I will have DAG, but my concern is for CAS NLB; the NLB hostname will be same name and IP of their existing exchange hostname webmail.xxx.com that is pointing to Exchange 2007, how can I do that without conflict?

You must change the Exchange 2007 name or use a different one for Exchange 2013.

Could you not use something like exchange02.webmail.domain.com for the NLB name and then when you're ready to cut over, delete the existing A record for webmail.domain.com and create it as a cname which points to exchange02.webmail.domain.com?

In addition to that

when planning to migrate from Exchange 2007 to 2013, you may walk through this informative technet blog that covers all the required aspects and provides step-wise assistance to accomplish this job :http://blogs.technet.com/b/meamcs/archive/2013/07/25/part-1-step-by-step-exchange-2007-to-2013-migra...

Moreover, while need to migrate users mailboxes, you may also look into LepideMigrator for Exchange that would be a nice alternative approach for you. It provides the option to migrate users mailboxes without any downtime.