After you've upgraded one or more of your domain controllers to Windows Server 2003, you need to do some additional tasks to fully complete the migration. First and foremost, you need to monitor the domain controllers every step of the way and especially after they have been upgraded. You are setting yourself up for failure if you are not adequately monitoring Active Directory.
The criticality of monitoring cannot be overstated. If you are not monitoring, how can you determine whether something broke during the upgrade? Here are several things you should check after you upgrade your first domain controller in a domain, any FSMO role owner, and after all DCs have been upgraded:
Query LDAP, Kerberos, GC (if applicable), and DNS (if applicable) and be sure authentication and login requests are being processed. The dcdiag command can run many of these tests.
Trend processor and memory utilization for some period before you do the upgrade so you can compare to the numbers after the upgrade.
The growth of the DIT should not be significant. You may in fact want to do an offline defrag after the upgrade to reclaim any space due to single- instance store of ACLs.
This is a no-brainer, but you should always check the event logs to see whether any errors are being logged.
Ensure that all of the SRV, CNAME, and A records for the domain controllers are registered. The dcdiag command can perform these checks.
Run repadmin /showreps and repadmin /replsum and watch for anything out of the ordinary.
You may want to add a new setting to an existing GPO or create a new GPO and see if the settings apply on a client that should be receiving it.
This can consist of opening an Explorer window and browsing the available shares on the domain controller.
You can test this out by placing a test file in the SYSVOL share on a domain controller and waiting for it to replicate to the other domain controllers.
This is not a comprehensive list of everything you should possibly monitor, but it is a good start. If everything checks out over a period of a week, you can feel pretty comfortable that the upgrade was successful. If nothing else, as long as you keep a close eye on the event logs, you should be able to catch the majority of problems.
After you feel comfortable that the upgrades have completed successfully, your next step should be to start raising the functional levels. If you've only upgraded the domain controllers in a single domain, you can raise the functional level for only that domain to Windows Server 2003. If you've upgraded all the domain controllers in the forest, you can also proceed to upgrade the forest functional level to Windows Server 2003.
After you raise the functional level of a domain or forest, you should add some additional steps to what you monitor to include testing out new features in Windows Server 2003. For example, to test the Windows Server 2003 domain functional level, you should log on to a domain controller and view the lastLogonTimestamp attribute of your user object that we discussed earlier in the chapter. This is a new replicated attribute that will contain your logon time. If after a period of time, you don't see that attribute getting populated, you'll need to dig deeper to determine what is going on.
Perhaps the easiest test to determine whether a functional level has been set for a domain or forest is to query the Root DSE and look at the domainFunctionality and forestFunctionality attributes. A value of 2 indicates the domain or forest is at the Windows Server 2003 functional level.
Once the functional levels have been defined, you'll want to tweak any settings that you discovered during your testing that are set differently than what you want or what you have configured previously. Of special interest should be the settings related to security and account lockout. If you need to disable SMB Signing, you can do so via Group Policy in the Domain Controller Policy Windows Settings Security Settings Local Policies Security Options Digitally Sign Communications.
A common pain point for Windows 2000 Active Directory administrators was account lockouts. All of the bug fixes that were incorporated into Service Packs 2 and 3 are included in Windows Server 2003. You may want to revisit your account lockout and password expiration settings. Microsoft's recommendations are included in their Security Template file located at %SystemRoot%\security\templates\SECUREDC.INF on a Windows Server 2003 domain controller.
If you had to hardcode any settings on domain controllers in the Registry, you should reevaluate those settings to see whether you still need them. For example, many people increased the intrasite replication frequency from 5 minutes to 15-60 seconds. With Windows Server 2003, the default frequency has changed to 15 seconds.
After you've upgraded your domain controllers and raised the functional level of a domain or forest, you are ready to start taking advantage of the new features. Some of them, such as the MMC and CLI enhancements, you can start utilizing immediately. With others, such as quotas, you'll want to think out exactly how to implement them and have them properly documented and communicated before you start using them. If you are using AD-Integrated DNS zones, you should look at converting to application partitions to store DNS data. This is a fairly easy conversion that can be done with the DNS MMC snap-in. In some cases, you may need to completely rethink your current processes. For example, if you start using the "Install from media" feature, you may change how you build and deploy domain controllers.