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”.

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:

Joint\contiguous namespace – the internal Exchange infrastructure namespace

and the external Exchange namespace are based on the public domain name

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

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.

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 Joint\contiguous

namespace, for example:

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 internal\external 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.

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.

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:

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.

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.

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.

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 use\have 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).

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

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 "CAS2010\Rpc (Default Web Site

)" -IISAuthenticationMethods NTLM,Basic

The PowerShell command that we use for setting

the ClientAuthenticationMethodauthentication to use basic is:

PowerShell

Set-OutlookAnywhere -Identity "CAS2010\Rpc (Default Web Site)" -ClientAuthenticationMethod:Basic

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