Migration Requirements
To ensure optimal performance and reliability from your server environment and that Windows® Essential Business Server functions properly, you need to migrate the Domain Name System (DNS) to Windows EBS as soon as the Windows EBS installation is complete. The specific migration steps depend on whether DNS in your existing environment was integrated with Active Directory®.
Important
This migration is mandatory.
Important
If you are migrating from Windows Small Business Server 2003 (Windows SBS), you must complete this migration and decommission your Windows SBS server within seven days of installing Windows EBS. You can extend this grace period to 21 days by installing a software update for Windows SBS 2003 that supports the “join domain” migration of Windows SBS data and settings. For additional instructions about how to migrate from Windows SBS to Windows EBS, see the Microsoft Web site (https://go.microsoft.com/fwlink/?LinkId=123374).
It is recommended that you read all the sections of this document before you start the migration.
If you are unfamiliar with DNS, read Background Information later in this document before you continue.
If you already understand what this migration covers, advance to Step-by-Step Migration later in this document.
Preparing for the migration
Your existing DNS server must support RFC-compliant zone transfers. Examples of DNS servers that support this are versions of Windows® 2000 Server, Windows Server® 2003, and Windows Server 2008, BIND 8.x, and several other UNIX DNS servers.
This migration instructs you to configure your environment to use root hints for DNS queries outside your organization (instead of using forwarders). This is the DNS configuration that is recommended for midsize companies. This is to avoid a scenario where the DNS server that you are using as a forwarder shuts down, and DNS queries outside your organization fail.
A common misconception is that using root hints vastly increases Internet bandwidth consumption. This is not true—DNS servers inside your organization will cache results to avoid queries outside your organization wherever possible.
Time estimate
You will need approximately one hour to complete this task. The time needed depends on the operating system that is running on your existing DNS server.
Decision flowchart
Study the following flowchart to determine which step-by-step instructions you should start with. If you are unsure where to start after you study the flowchart, read the following topics for more information:
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Figure 1 How to determine where to start your migration
Migration overview
The following table provides an overview of what will be migrated.
| Target State | Benefit | Start State | Action |
|---|---|---|---|
|
DNS zone for the domain for Windows EBS is integrated with AD DS |
Higher reliability Multiple primary DNS servers for a single zone |
DNS zone for the domain for Windows EBS is not integrated with AD DS |
See Step-by-Step Migration section |
|
DNS zone for the domain for Windows EBS is already integrated with AD DS |
None |
||
|
The primary DNS server for the domain Windows EBS is joined to your Management Server. Your existing DNS server is decommissioned. |
Secure dynamic updates avoid scenarios where multiple DNS servers are out of sync |
The primary DNS server for the domain for Windows EBS is a domain controller on your existing DNS server |
See Step-by-Step Migration section |
|
You did not have DNS Server service prior to installing Windows EBS |
None |
||
|
You chose to create a new forest during the Management Server installation (possibly because you did not have AD DS prior to installing Windows EBS) |
None |
||
|
DNS Server service on the Management Server and Messaging Server is configured and running |
Higher reliability |
DNS Server service on the Management Server and Messaging Server is not configured and not running because you joined a domain that already had a primary DNS server |
See Step-by-Step Migration section |
|
DNS Server service on the Management Server and Messaging Server is configured and running because you created a new forest during the Management Server installation (possibly because you did not have AD DS prior to installing Windows EBS) |
None |
||
|
The Management Server and Messaging Server are the only DNS servers in your environment |
Avoidance of scenarios where multiple DNS servers are out of sync |
DNS Server service on existing servers is configured and running |
See Step-by-Step Migration section |
|
No DNS server present in environment |
None |
||
|
All computers in the environment are using Windows EBS for DNS requests |
Avoidance of scenarios where multiple DNS servers are out of sync |
Client computers and existing servers are using existing DNS servers for DNS requests |
See Step-by-Step Migration section |
|
No DNS servers present in environment |
None |
||
|
DNS servers are using root hints |
Higher uptime by avoiding dependencies on upstream DNS servers |
DNS servers are using forwarders |
See Step-by-Step Migration section |
|
DNS servers are using root hints |
None |
If something goes wrong
If something goes wrong before you set your existing DNS server as a secondary DNS server, your existing DNS server is still the primary DNS server for name resolution, so there is no impact to your network. You can troubleshoot without further issues in the meantime.
If something goes wrong after setting your existing DNS server as a secondary DNS server, revert to your original configuration by changing the type of your existing DNS server from secondary to primary. While your existing DNS server is a secondary server, existing computers will still be able to use it for name resolution, so there is minimal impact to your network. As the following instructions indicate, do not change your DNS settings in Dynamic Host Configuration Protocol (DHCP) or on statically addressed computers if you had issues with an earlier part of this migration.
For more information, see Additional References later in this document.