Misc
Utilities
Exchange 5.5 is typically used in a Windows NT 4.0 domain environment,
Exchange 2000 is strictly a Windows 2000 platform. Your preperation requires
an upgrade to Windows 2000 Server and AD first. You must deploy AD in your
environment if you are planning to install Exchange 2000.
To avoid the installation of separtate Windows 2000 domains, consider
upgrading the PDCs in your domain environment directly. This method preserves
all account information, including the original security identifiers (SIDs).
However, upgrading the PDC involves an additional configuration step if your
PDC also runs Exchange Server. Exchange 2000 is unable to work with Windows
NT 4.0 based security information. This includes the Site Services account
used to communicate with previous Exchange Server versions. Because Exchange
2000 needs to use the Site Services account, you must first upgrade the PDC
of the domain in which this special account exists. During this upgrade, the
Site Services account is converted into a Windows 2000 security principal.
You don't need to upgrade your entire NT 4.0 environment to Windows 2000 to
upgrade to Exchange 2000, however it is a good idea to upgrade at least the
PDCs of all your user domains.
You can install Windows 2000 in seperate doamins and using the AD Migration
Tool to clone the existing security information. Cloned accounts are specific
Windows 2000 accounts for which properties and group memberships have been
copied from corresponding NT 4.0 source accounts. Although the account
objects will have a different primary SID than their source accounts, each
source account's SID is copied to the SIDHistory attribute of the
corresponding clone. Through the old SID preserved in the SIDHistory
attribute, the Windows 2000 user can access all network resources available
to the source account - provided that trusts exist between the NT doamins
and the clone's AD domain.
The AD Migration Tool is appropriate for complex Windows NT environments
consisting of multiple NT 4.0 domains because it allows consolidation of the
domain environment.
Microsoft recommends changing the LDAP port (389) for the Exchange 5.5
directory service prior to upgrading to Windows 2000 and AD.
The Active Directory Connector (ADC)
To ensure a common global address list for all users, whether they still
reside on Exchange 5.5 or are migrated to Exchange 2000, you need to
syncronize the directories with each other. To enable directory
synchronization, install the ADC and configure user connection agreements.
Connection agreements can replicate recipient and public information between
Exchange 5.5 and the Global Catalog. The ADC of Exchange 2000 of Exchange
2000 requires Exchange 5.5 SP3 be running on the Exchange 5.5 server you plan
to connect to.
Windows 2000 comes with a basic version of the ADC so that Exchange 5.5 can
operate in a Windows 2000 environment even if Exchange 2000 is not installed.
The Exchange 2000 version comes with another version of the ADC which comes
with advanced functionality. The Exchange 2000 version of the ADC updates the
AD schema on its first installlation.
When directory replication occurs b/w AD and Exchange 5.5 via the ADC, the
default configuration creates disabled Windows 2000 accounts for all Exchange
5.5 mailboxes that do not already have a matching AD object (account object).
When directory replication between Exchange 5.5 and Exchange 2000 occurs,
Exchange 2000 disguises itself as and Exchange 5.5 server. It also appears
in the Exchange Administrator (5.5) as a 5.5 server. This feature is possible
via the Microsoft Exchange Site Replication Service (SRS / SRSMAIN.EXE). The
transaction logs reside in \exchsrvr\dsadata\ with an in place upgrade and in
\exchsrvr\srsdata\ when joining an existing site. When installing or enabling
SRS, all existing Exchange 2000 administrators inherit the permissions to
manage the SRS environment. Administrators that have been granted permissions
in Exchange System Manager at a later time are unable to manage SRS. To grant
these administartors SRS permissions, use the Exchange Adminstator program
and connect to the Exchange 2000 server. Grant the desired user account the
appropriate rights, such as Service Account Administrator, as usual at the
organization, site, and configuration level. You need the rights of a
Permissions Admin.
If you are installing a first Exchange 2000 server on a Windows 2000 DC not
running any previous version of Exchange and joining an existing site, SRS
automatically uses TCP port 379 to avoid LDAP port conflicts with AD.
Exchange 5.5 uses RPC for intrasite replication. All Exchange servers in a
site must validate each other using a common Site Services account before
server to server communications is allowed. Servers not using the correct
Site Services account will not be able to communicate. Exchange 2000 must
use the common Site Services account for its communications with previous
Exchange versions. When joining an existing site, you will be prompted for
the Site Services account information. To modify the account password, use
Exchange System snap in when displaying the properties of the administrative
group that represents the site in question. Choose Modify on the General
property sheet to change the information displayed under Exchange 4.0/5.x
Services Account For This Site. The Site Services account specified in the
properties of an administrative group is only used for communications with
legacy Exchange systems. Exchange 2000 servers use the LocalSystem account
for their native communications.
Exchange 2000 server can utilize any existing connector installed in the site
because SRS, in conjunction with the ADC, replicates configuration
information, including information about connected sites and gateways, to
AD. Information about existing Exchange 2000 connectors is replicated to all
Exchange directories. Eariler versions of Exchange can, therefore, also use
new connectors for message transfer. Through directory replication, routing
information from servers running previous Exchange server versions is placed
in the Exchange 2000 Server link state table. This allows Exchange 2000
servers to include any existing connectors in its routing decisions.
The Outlook Web Access (OWA) in Exchange 2000 uses the Internet Server API
(ISAPI) componenent (DAVEX.DLL) and other DLLs instead of ASP pages,
therefore, any customized ASP pages you have made will no longer work once
you upgrade to Exchange 2000. You can, however, use an Exchange 5.5 box as a
front end for an Exchange 2000 server, but not vice versa.
To switch an organization to native mode, all computers running previous
versions of Exchange must be upgraded or removed. The Change Mode button in
the General property sheet of an organization running mixed versions of
Exchange is deactivated in the Exchange System snap in. Switching to native
mode is an irreversible process.
Although the move-mailbox upgrade represents an interesting alternative to
the in-place approach, a complete migration requires numerous manual
configuration steps. After you have removed a server running an earlier
version of Exchange from the site, you need to delete its references from
AD using the Exchange Administrator program. The last Exchange server must
be delete from the SRS database manually because no other Exchange directory
service exists in the site that could accomplish this via directory
replication.
Upgraded users now working with mailboxes on Echange 2000 will notice small
changes in the structure of the address book because they now connect to a
GC server for address lookups. Users might sometimes see duplicate accounts
in the address book, the duplicate accounts, which might have been generated
during the migration process, require a dedicated cleanup using the Active
Directory Account Cleanup Wizard. To use the AD Account Cleanup Wizard, look
in the Exchange program group. To avoid the generation of duplicate
accounts in your environment, upgrade all existing PDCs to Windows 2000
before configuring user connections agreements with the ADC.
Migration Summary
You must deploy Windows 2000 and AD if you are planning to install Exchange
2000. Because Exchange 2000 must use the Site Services account for its
communications with previous versions, you must first upgrade the PDC of the
domain in which the Exchange Site Services account exists. If you are
planning to directly upgrade an existing Exchange 5.5 system, you need to
upgrade its operating system as well, and possibly change the TCP port for
the LDAP interface of the Exchange directory service.
By upgrading the PDC, you migrate Windows NT user accounts to AD. The
corresponding mailbox information, however, still resides in the Exchange
directory. Consequently, you need to synchronize both directories via a
connection agreement to add the mailbox information to the user account
objects.
Whether you join an existing site with a new Exchange 2000 server or perform
an in-place upgrade, Exchange 2000 Server must replicate directory
information with earlier versions of Exchange Server, which is handled by
SRS. A configuration connection agreement transfers the directory information
from the SRS database into AD, where previous Exchange Server resources are
displayed as transpartent objects. In the Exchange Administrator program,
Exchange 2000 servers appear similar to servers running previous versions of
Exchange Server.
To switch an organization to native mode, all computers running previous
Exchange Server versions must be upgraded or removed. Switching to native
mode permanently disables interoperability with previous versions.
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