Installing and Configuring the Basics of Exchange Server 2013 for a Brand-New Environment (part 2)

4. Exchange Server 2013 Hardware Requirements

Recommended hardware requirements for Exchange Server 2013 servers vary depending on factors such as the server roles and anticipated loads; however, Microsoft maintains a list of minimum hardware requirements to install Exchange Server 2013.

Table 1 shows the minimum and recommended hardware requirements for Exchange Server 2013, as stated by Microsoft.

Table 1. Minimum Hardware Requirements

5. Understanding the Active Directory Requirements for Exchange Server 2013

An AD infrastructure running on Windows Server 2012, Windows Server 2008 R2 Standard or Enterprise, or Windows Server 2008 Standard or Enterprise must be in place before an organization can deploy Exchange Server 2013. Exchange Server depends on the services provided by AD to successfully function, and the design and implementation of the AD environment can have an enormous impact on the success of the Exchange Server deployment. Mistakes made in the planning or implementation of AD can be costly and difficult to correct later.

If AD is already deployed, it is important that the team designing the Exchange Server infrastructure have a solid understanding of the existing AD environment. Organizations with an AD infrastructure already in place need to evaluate how Exchange Server can fit into their environments. If AD has not been deployed, the organization or team designing Exchange Server needs to plan its implementation with a thought as to what their messaging infrastructure will look like.

Some of the AD factors that should be considered when deploying Exchange Server 2013 include the following:

• Global catalog server placement

• AD Sites and Services

• Forest and domain functional levels

• Flexible Single Master Operations role placement

• Permissions needed to install Exchange

• Bandwidth and latency in the network

As was the case in Exchange 2000 Server through Exchange Server 2010, Exchange Server 2013 requires a global catalog infrastructure to function. The global catalog maintains an index of the Active Directory database for objects within its domain. In addition, it stores partial copies of data for all other domains within a forest.

Just as important, Exchange Server relies on global catalog servers to resolve email addresses for users within the organization. Failure to contact a global catalog server causes emails to bounce, as the recipient’s name cannot be resolved.

Active Directory Sites and Services

In Exchange Server 2003 and earlier, Exchange Server utilized a dedicated routing topology for transporting messages throughout the organization. Beginning with Exchange Server 2007, Microsoft redesigned the product to be a site-aware application. This continues in Exchange Server 2013.

Site-aware applications are able to determine what site they (and other servers) belong to by querying Active Directory. The site attribute of all Exchange Server objects is maintained by the Microsoft Exchange Active Directory Topology Service. In addition, Exchange Server 2013 servers utilize site membership to identify which domain controllers and global catalog servers should be utilized to process Active Directory queries.

The Exchange Server 2013 servers utilize Active Directory site membership as follows:

• Client Access servers—When a Client Access server receives a connection request from a user, it contacts AD to determine which Mailbox server houses the user’s mailbox and which site that server belongs to. If the Mailbox server is in a different site, the connection may be redirected to a more suitable Client Access server in the same site as the Mailbox server, if one exists. Otherwise, the Client Access server proxies the request to the Mailbox server that houses the currently active copy of the database that contains the user’s mailbox.

• Mailbox servers—The Mailbox servers use Lightweight Directory Access Protocol (LDAP) to access recipient, server, and organization information from AD.

Forest and Domain Functional Levels

With each new edition of the Windows Server and Exchange Server operating systems, new functionalities are introduced. Some of these enhancements require that the Active Directory infrastructure be upgraded before you can take advantage of the new capabilities. At times, these capabilities cannot be implemented until all domain controllers in an environment have been upgraded to the same level.

To support this, Active Directory has forest and domain functional levels that determine what enhancements are enabled or disabled. By raising the functional level of an environment, new functionalities are enabled. By maintaining an older functional level, interoperability with older domain controllers is supported.

Forest Functional Levels

Windows Server 2003 supports three forest functional levels:

• Windows 2000 Native—Required while any Windows 2000 Server domain controllers remain in your forest. Supports domain controllers running Windows NT 4.0, Windows 2000 Server, and Windows Server 2003.

• Windows Server 2003 Interim—A special functional level only implemented during Windows NT 4.0 to Windows Server 2003 upgrades.

• Windows Server 2003—All DCs in the forest must be running Windows Server 2003, and all domains in the forest must be at the Windows Server 2003 domain functional level before you can raise your forest functional level to Windows Server 2003.

Windows Server 2008 supports three forest functional levels:

• Windows 2000 Native—Supports Windows 2000 Server, Windows Server 2003, and Windows Server 2008 domain controllers

• Windows Server 2003—Allows for a mix of Windows Server 2003 and Windows Server 2008 functional level domains

• Windows Server 2008—Ensures all domain controllers in the forest are running Windows Server 2008 and all domains have been raised to the Windows Server 2008 domain functional level

Windows Server 2012 supports three forest functional levels:

• Windows Server 2003—Allows for a mix of Windows Server 2003 and Windows Server 2008 functional level domains

• Windows Server 2008—Ensures all domain controllers in the forest are running Windows Server 2008 and all domains have been raised to the Windows Server 2008 domain functional level

• Windows Server 2012—Ensures all domain controllers in the forest are running Windows Server 2012 and all domains have been raised to the Windows Server 2012 domain functional level

Domain Functional Levels

Windows Server 2008 supports three domain functional levels:

• Windows 2000 Native—Allows domain controllers running Windows Server 2008 to interact with domain controllers running either Windows Server 2008, Windows Server 2003, or Windows 2000 Server

• Windows Server 2003—Supports an environment composed of a mixture of Windows Server 2003 and Windows Server 2008 domain controllers

• Windows Server 2008—Only available after all domain controllers in a domain are running Windows Server 2008

Windows Server 2012 supports three domain functional levels:

• Windows Server 2003—Supports an environment composed of a mixture of Windows Server 2003 and Windows Server 2008 domain controllers

• Windows Server 2008—Supports an environment composed of a mixture of Windows Server 2008 and Windows Server 2012 domain controllers

• Windows Server 2012—Only available after all domain controllers in a domain are running Windows Server 2012

Note

To install Exchange Server 2013, the Active Directory domain functional level must be Windows Server 2003 or higher for each domain in the Active Directory forest that will house an Exchange Server 2013 server.

Windows 2000 Mixed, Windows 2000 Native, and Windows Server 2003 Interim modes are not supported.