I work a lot with Active Directory-related tasks. One of the tasks is to know the group membership of critical Active Directory Groups such as Domain Admins, Enterprise Admins, Schema Admins, Event Log Readers, and a few others that are a bit less known. As I did it, I got bored of typing the group names repeatedly and decided that enough was enough and there must be an easier way for me to do that.
In my earlier blog post, I showed you a way to find duplicate DNS entries using PowerShell, but the focus was on finding duplicate entries based on hostname. But what if you would like to find duplicate entries based on IP Addresses? This was the question I was asked on Reddit, and I thought it was a legitimate request, so today’s focus will be on transposing table output from earlier functions to present data differently.
Today’s blog post is about Active Directory-integrated DNS and how to find duplicate entries. By duplicate, I mean those where one DNS name matches multiple IP addresses. While some duplicate DNS entries are expected, in other cases, it may lead to problems. For example, having a static IP assigned to a hostname that later on is also updated with dynamic entries.
Duplicate SPNs aren’t very common but can happen in any Active Directory as there’s no built-in way that tracks and prevent duplicate SPN’s. One has to either know all SPN’s in the environment, track them or check each time whether it already exists or not. Things get more complicated with larger Active Directory environments as people change, new apps are added, old apps are forgotten, but SPNs prevail.
If you ever encounter an error while trying to create a new domain within a forest saying, “The replication operation encountered a database error,” it makes you sweat a bit. Your brain tells you it will be a nightmare to fix, do I have proper backups to make it happen, and the question “why now” shows up.
Some time ago, I wrote a blog post on checking for LDAP, LDAPS, LDAP GC, and LDAPS GC ports with PowerShell. It mostly works, but it requires a tad bit of effort, and it doesn’t cover the full scope that I wanted. Recently (well over 3 years ago), Chris Dent shared some code that verifies the LDAP certificate, and I thought this would be good to update my cmdlets to support just that with a bit of my own magic on top.
I’ve been working on cleaning up Group Policies for a couple of months. While it may seem trivial, things get complicated when you’re tasked with managing 5000 GPOs created over 15 years by multiple teams without any best practices in mind. While working on GPOZaurr (my new PowerShell module), I’ve noticed that the more code I wrote to manage those GPOs, the more I knew passing this knowledge to admins who will be executing this on a weekly/monthly basis is going to be a challenge. That’s why I’ve decided to follow a similar approach as my other Active Directory testing module called Testimo. I’ve created a single command that analyses Group Policies using different methods and shows views from different angles to deliver the full picture. On top of that, it provides a solution (or it tries to) so that it’s fairly easy to fix – as long as you agree with what it proposes.
Active Directory Trusts are useful to connect one or more domains. But as useful those are, they can be very dangerous. Also, keeping trusts working and in good shape should be a top priority for Active Directory Admins. While there is a couple of command in the Active Directory module Get-ADTrust, I thought I would try and write my own that checks a few more things. I want to thank Chris Dent for his input on the part of this command. His binary skills amaze me!
In the Active Directory PowerShell module, you have two commands to your disposal that help display group membership. Those are Get-ADGroup and Get-ADGroupMember. The first command contains property Members, which gives you DistinguishedName of all members, and Get-ADGroupMember can provide you either direct members or with Recursive switch all members recursively (skipping groups). Till a few weeks ago, I was a happy user of those commands until I noticed two things. Member property for Get-ADGroup sometimes misses elements for whatever reason.
I’m pretty addicted to reading blog posts. I saw this new blog post the other day, where the author created the DHCP HTML report, and he did it by manually building headers, footers, table borders, and finally, adding some coloring to the percentage of DHCP being in use. It’s the “standard” approach to build HTML in PowerShell, and I’ve seen a similar path before, but that got me thinking how much time it would take for me to replicate the very same functionality using PSWriteHTML module.