Scenario:
You have been tasked with completing an Active Directory
Health Check, what should you do?
Walkthrough:
This step-by-step guide takes you through 7 steps with things
to include in an Active Directory Health Check (ADHC.) It is roughly ordered by
what is most important/should be done first, and proceeds in order to obtain
more and more information as and when the time permits.
Note: To make life
easier, there are software packages out there like Quest’s Spotlight on Active
Directory (latest version 6.8.1) which are well worth trialing-out/investing-in.
The following post only covers freely available tools.
Step 1: Run the
Microsoft Active Directory Topology Diagrammer (ADTD)
This will need a workstation on the domain, with
Microsoft Visio installed.
Obtain “ADTD.Net Setup.msi” from here .
Install and run “ADTD.exe”.
Populate the Server/Domain box, and run through the tabs
ticking off what is to be included in the Visio output (the more detail the
better) > click Discover! > click Draw!
This will provide a lot of useful information - FSMO role
holders, Operating System and Service Pack Level of Domain Controllers, Site
Links …
Fig. Example ADTD
Domains Output
Fig. Example ADTD
Sites Output
Step 2:
(Windows 2008 R2 domain controllers) Active Directory Domain Services and DNS
Server Best Practices Analyzer
One of the great
things about Windows Server 2008 R2 was the inclusion of Best Practice Analyzer’s
for all roles. Even if there is only one 2008 R2 domain controller in the
domain, this can be used to gain valuable information.
The BPA is located in Server Manager > Roles >
Active Directory Domain Services > Scroll down to find ‘Best Practices Analyzer’
and click ‘Scan This Role’
Similarly, the DNS Server BPA is located in Server
Manager > Roles > DNS Server > Scroll down to find ‘Best Practices
Analyzer’ and click ‘Scan This Role’
Step 3: Command
Prompt CLI Commands
From a domain controller, run the commands - below in
bold - via the command prompt (can be piped to a text file by appending >
textfilename.txt at the end):
Note 1: If running
on a DC prior to Server 2008, you will need to install the Windows Server 2003
Administration Tools Pack (Adminpak) from here
Note 2: Instead of
manually running the below, can use the Active
Directory Health Check script from thesysadmins
Find System Boot
Time and Uptime:
systeminfo | find “System
Boot Time:”
systeminfo | find “System
Up Time:”
Display current
TCP/IP network configuration:
ipconfig /all
Analyze the state
of domain controllers in a forest:
dcdiag /a
Provide an overview
of any replication failures, and if last replication attempts were successful:
repadmin
/replsummary
repadmin /
showrepl
Update: Instead of using repadmin, check out the new Active Directory Replication Status Tool (ADREPLSTATUS) which is currently in version 1.0, requires .NET Framework 4, and is for Server 2003 DCs and above.
Returns the FSMO
roles holders:
netdom query fsmo
Step 4: Active
Directory Sites and Services (ADSS)
·
Are site objects created for every geographical
site?
·
Are subnets object created for every subnet?
·
Are subnets correctly assigned sites?
Step 5:
Decommissioned/Rogue DCs
Sometimes DCs are decommissioned/die without being removed
from Active Directory using DCPROMO (the ADTD might pick up old DCs):
·
If the DC is not tombstoned then DCPROMO the DC
·
If the DC has been decommissioned but is still
in ADSS, then delete from ADSS, also remove traces from Active Directory Users
and Computers (ADUC), and DNS.
·
Advanced DC removal requires using NTDSUTIL Metadata
Cleanup, and - if that is not possible - then ADSIEDIT.
Step 6: Check Domain
Controllers for …
·
IP
Configuration: Is the subnet configured correctly? Are DNS servers
configured correctly - domain PDC should be first, then the DC itself or
another local DC (if the PDC) second, then 3rd and 4th
can be the higher level (root domain) PDC and Secondary DNS servers (if a child
domain)?
·
Time:
All DCs should be in time synchronization with the root domain PDC - find the
time on the PDC (taking time zones into account) and verify….
·
Windows
Firewall: Inbound ports - UDP/TCP 53, 88, 389, 464; UDP 123, 137; TCP 139,
445, 3268
Fig. Domain
Controller Inbound ports
Step 7:
Additional Investigations
·
Active Directory design - OUs and objects
·
Security and Group Policy
·
Wireshark/Network Analysis - for dropped packets
to/from DCs
Hi, a few weeks ago I stumbled upon a tool from Microsoft - it's called Active Directory Replication Status Tool
ReplyDelete(http://www.microsoft.com/en-us/download/details.aspx?id=30005).
It's a good GUI replacement for the CLI commands and it helps to prioritise on errors. Give it a try.
Hi Bitflip, thank you very much for the comment. I have added an update to the post underneath where repadmin is mentioned, to suggest using ADREPLSTATUS instead. It looks like an interesting new tool. Cheers!
DeleteActive Directory Health Check and Repadmin
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How about using Dynamic AD Replication Checker Tool - An advanced tool for experienced AD Administrators at www.Dynamic-SpotAction.com
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Here is a detailed article that will show you how to perform a health check for your Active directory, DC's, DNS, Replication - http://www.networkangel.net/active-directory-health-check-tools
ReplyDeleteActive Directory Health Profiler is a tool that in my view is one of the very best in Active Directory Health management. I think we should give this one a try?
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Best,
John