The checklist for preparing your Exchange 2010 infrastructure for Exchange 2013 coexistence |10#23 http://o365info.com/the-checklist-for-preparing-your-exchange-2010-infrastructure-for-exchange-2013-coexistence/ A short preparation checklist for the project of: Exchange 2013/2010 coexistence environment, in which we review some of the components and infrastructure that we will need to prepare. Eyal Doron | o365info.com

1. Page 1 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
THE CHECKLIST FOR PREPARING YOUR
EXCHANGE 2010 INFRASTRUCTURE FOR
EXCHANGE 2013 COEXISTENCE | 10#23
In the current article focus on the preparation that we will need to implement in the
existing Exchange 2010 environment for a project of: implementing Exchange
2013/2010 coexistence environment. Generally speaking, the good news is that the
Exchange 2013 and Exchange CAS 2010 are “good friends”.

2. Page 2 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
Versus the scenario of Exchange 2013/2007 coexistence environment that required
more comprehensive adjustment of a URL address, namespace, host name, etc.,
the amount of the adjustments that we need to implement in the Exchange CAS
2010 infrastructure are minimal because the Exchange 2013 and the Exchange CAS
2010 infrastructure will use the same or an identical namespace.
Exchange 2010 namespace – scenario
description
The preparation that we will need to implement regarding the Exchange 2010 CAS
namespace depends on the specific charters of the organization.
To simplify, let’s assume that in our scenario, the following rules are applied:
 Jointcontiguous namespace – the internal Exchange infrastructure namespace
and the external Exchange namespace are based on the public domain name

3. Page 3 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
suffix: o365info.comthe internal and the external host name who points to the
Exchange 2010 CAS are:mail.o365info.com
 The organization uses Split DNS configuration – internal DNS infrastructure that
hosts the domain name: o365info.com + External DNS infrastructure that hosts
the domain name:o365info.com
 Autodiscover infrastructure – The internal and the external Autodiscover
namespace are:
autodiscover.o365info.com
Exchange 2010 namespace versus Exchange
2013 namespace
Despite the image “message”, in reality, the Exchange 2010 namespace and the
versus Exchange 2013 namespace functioning properly with each other.
The major concept is that in Exchange 2013/2010 coexistence environment, we will
continue to use the same namespace as we use in the Exchange 2010 CAS

4. Page 4 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
environment, but the “change” is that we will “repaint” the Exchange records that
point, until now, to the Exchange 2010 to the “new Exchange infrastructure” – the
Exchange 2013 infrastructure.
Exchange namespace and DNS infrastructure
In the following diagram, we can see an example to the “re point” concept. Before
the implementation of the Exchange 2013/2010 coexistence environment, the
public DNS records of the Autodiscover and the Public facing Exchange CAS server
host name were pointing to the Exchange 2010 CAS.
After the implementation of the Exchange 2013/2010 coexistence environment, the
public DNS records of the Autodiscover and the Public facing Exchange CAS server
host name will point to the Exchange 2013 CAS.

5. Page 5 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
In a Split DNS infrastructure, the updates of the DNS records will need to be
implemented for the internal DNS infrastructure and the External DNS
infrastructure,
In the following diagram, we can see an example of the required DNS configuration
settings.
Exchange 2013/2010 coexistence environment
– Internal Autodiscover infrastructure
considerations
Based on the assumption of our scenario in which the Exchange 2010 Autodiscover
namespace infrastructure was based upon the concept of Jointcontiguous
namespace, for example:

6. Page 6 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
autodiscover.o365info.com, we will need to verify the implementation of the
following requirements.
 DNS Infrastructure – verify that the internalexternal DNS infrastructure will be
updated by “mapping” the Autodiscover record to the IP address of the Exchange
2013.
 Verify that the Exchange 2013 CAS will be registered at the Active Directory SCP
using the host name: autodiscover.o365info.com
In the following diagram, we can see the implementation of the internal
Autodiscover infrastructure in an Exchange 2010 environment.
1. Exchange 2010 client query Active Directory for the name of the Autodiscover
Endpoint and the answer is: autodiscover.o365info.com
2. The Exchange 2010 client query DNS for the IP address of the host:
autodiscover.o365info.com and the “DNS answer” include the IP address of the
Exchange 2010 CAS.

7. Page 7 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
In the following diagram, we can see the implementation of the internal
Autodiscover infrastructure in Exchange 2013/2010 coexistence environment.
1. Exchange 2010 client query Active Directory for the name of the Autodiscover
Endpoint and the answer is: autodiscover.o365info.com
2. The Exchange 2010 client query DNS for the IP address of the host:
autodiscover.o365info.com and the “DNS answer” include the IP address of the
Exchange 2013 server.
3. The Exchange 2010 client will address the Exchange 2013 CAS and the Exchange
CAS server will proxy the request to Exchange 2010 CAS.

8. Page 8 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
Other considerations
When implementing an Exchange 2013 coexistence environment, there are many
other additional elements and consideration that need to be “included” in the
preparation checklist.
Note – in case that you need to get more information about the required
preparation in a scenario that is similar to the scenario that we use in the following
article, you can read the information in the: Exchange Server Deployment Assistant
Just a little taste of the additional requirements could be:

9. Page 9 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
 DNS infrastructure and MX records
In a scenario of Exchange 2013 coexistence environment, we will need to point to
MX records to the “new Exchange 2013 CAS” that will be configured as the Public
facing Exchange CAS server instead of the former Exchange 2010 CAS.
 Firewall infrastructure
We will need to update the Firewall rule that relates to the mail infrastructure
was pointed to the IP address of the Exchange 2010 server to the “new IP
address” of the Exchange 2013 server.
Exchange 2010 namespace in Exchange 2013
coexistence environment
The term that is use for describing the relationship that exists between the
Exchange 2010 infrastructure namespace and the Exchange 2013 infrastructure
namespace is: “the twin’s namespace concept”.
The meaning of this term is that booth of the infrastructures (Exchange CAS
2013/2010) will use the same namespace.
Exchange clients should address the Exchange CAS 2013 is a “focal point” for all of
the availability services such as: Autodiscover, access to mailbox and Exchange web
service.
The Exchange CAS 2013 will accept the Exchange client requests and in case that
the Exchange client is: Exchange 2010 client, the Exchange CAS 2013 will “know
what to do” with the request.
In other words: there is no need for using a dedicated or a specific namespace for
the Exchange CAS 2010 infrastructure.

10. Page 10 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
In the following table we can see a summary of the namespace infrastructure in
Exchange 2013/2010 coexistence environment. It’s easy to see that the Exchange
2010 namespace is identical to the Exchange CAS 2013 namespace.

11. Page 11 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
In the following diagram, we can see an example of the required configuration
setting in Exchange 2010 infrastructure that relates to the Exchange 2010 URL
address and services.

12. Page 12 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
Implementing the required updated in
Exchange 2010 infrastructure | Outlook
Anywhere infrastructure
As mention, in an Exchange 2013/2010 coexistence environment we will need to
verify that:
1. Exchange CAS 2010 include Outlook Anywhere support
2. The Outlook Anywhere usehave the required configuration settings
The required setting that relates to Outlook Anywhere service, that we will need to
implement in the Exchange 2010 infrastructure are as follows:
1. External host name
Verify if the Exchange CAS 2010 supports the Outlook Anywhere services.
Case 1: in case that the Exchange CAS 2010 support Outlook Anywhere services, we
will need to update the authentication protocol setting (in the next section – xxx we
will relate to the authentication protocol setting).

13. Page 13 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
Case 2: in case that the Exchange CAS 2010 doesn’t support Outlook Anywhere
services, we will need to enable the Outlook Anywhere services and for the value of
the external host name choose the host name that is “used by Exchange CAS 2013”.
For example, in our scenario, we will configure the external host name as:
mail.o365info.com
External host name
Outlook
Anywhere
We will need to verify that the value of the external host name
uses the primary namespace. In our scenario, the external host
name is: mail.o365info.com.
2. External client authentication protocol
We will need to verify that the value of the “External client authentication” is set of
basic
3. IIS authentication method
We will need to configure the value of the: ”IIS authentication method“ to: basic and
NTLM

14. Page 14 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
Mange and update the Exchange 2010 – Outlook Anywhere settings
In Exchange 2013/2010 coexistence environment, Exchange 2010 client Outlook
client will address the Exchange CAS 2013 and the Exchange CAS 2013 will proxy
the communication request to the Exchange CAS 2010.
To be able to “CAS to CAS” communication, we will need to set the value of
theIISAuthenticationMethods to: NTLM and basic authentication
Additionally, set the ClientAuthenticationMethod to basic
The PowerShell command that we use for setting
the IISAuthenticationMethodsauthentication to use NTLM and basic is:
PowerShell
Set-OutlookAnywhere -Identity "CAS2010Rpc (Default Web Site
)" -IISAuthenticationMethods NTLM,Basic
The PowerShell command that we use for setting
the ClientAuthenticationMethodauthentication to use basic is:
PowerShell
Set-OutlookAnywhere -Identity "CAS2010Rpc (Default Web Site)"
-ClientAuthenticationMethod:Basic

15. Page 15 of 15 | Part 10#23 | The checklist for preparing your Exchange 2010 infrastructure
for Exchange 2013 coexistence
Written by Eyal Doron | o365info.com | Copyright © 2012-2015
The PowerShell command that we use for viewing the setting of the Outlook
Anywhere settings is:
PowerShell
Get-OutlookAnywhere -Server CAS2010
Additional reading
 Ambiguous URLs and their effect on Exchange 2010 to Exchange 2013 Migrations
 Client Connectivity in an Exchange 2013 Coexistence Environment
 Exchange 2013 Client Access server configuration
Script for collecting information about existing Exchange infrastructure
 Generate Exchange Environment Reports using Powershell
 Exchange Email Organization Report (Get-CorpEmailReport)
The Exchange 2013 coexistence article series index page