Audit GPO Changes
Audit GPO Changes KB ID 0001920 Problem If you are reading this your either replanning ahead (bravo!) or there’s been an incident that you are concerned about. If that is the case its important to remember that “you cannot audit retrospectively”* *Note: you can find out when GPOs were altered, but not by whom, with some simple PowerShell i.e. Get-GPO -All | Select-Object DisplayName, ModificationTime Group Policies are...
Windows Certificate Services – Setup a CRL
Setup a CRL KB ID 0000957 Problem One of the often-overlooked tasks in a Public Key Infrastructure (PKI) deployment is configuring your Certificate Services Certificate Revocation List (CRL). For smaller deployments with only one server, you don’t need to worry about complex design considerations (though a CRL doesn’t have to be hosted on a Certificate Services server). In my test environment, I have only one PKI server,...
Cisco ASA Domain Authentication and Trust (Allowing)
ASA Domain Authentication KB ID 0000973 Problem I cringed this morning when I was asked about this, last time I had to get a client to authenticate to a domain through a firewall, it was ‘entertaining’. The problem is Windows loves to use RPC, which likes to use random ports, so to make it work you either had to open TCP ports 49152 and 65535 (Yes I’m Serious). Or you had to registry hack all your domain controllers...
Windows Server 2025 Trust Relationship Failures Post-Upgrade
2025 Trust Relationship KB ID 0001917 Problem Following a full upgrade of all domain controllers (DCs) to Windows Server 2025, organisations may experience trust relationship failures between domain-joined workstations and the domain. This issue predominantly affects clients running Windows 10/11 versions up to 23H2. Notably, environments retaining at least one older DC do not encounter this problem. Symptoms Users unable to log in to...
Windows Displaying a Logon Notice (legal notices)
Logon Notice KB ID 0000328 Problem It’s been a while but when I was asked my notes were seriously out of date .Should you with to enable this feature then do the following. Solution : Logon Notice Logon Notice Option 1 – via Domain Policy 1. On a domain controller, Start > administrative tools > Group Policy Editor > Either edit an existing policy or create a new one (Remember its a computer policy you need to...
Updating Domain Computer Objects with Last Logon and Machine Information
Last Logon KB ID 0001340 Problem I can’t really take the credit for this, I was at a client’s site a few weeks ago, and they were doing this. I thought ‘That’s cool, I’ll have a play with that when I get the chance”. Essentially, you update the description of the Computer object(s) in AD so that they list; The last user who logged on. What time they logged on. What AD ‘Site’ the machine...
Disaster Recovery Planning for AD & Entra ID
Disaster Recovery Planning KB ID 0001911 Problem When Disaster Recovery Planning for Active Directory (AD) and Entra ID (formerly Azure AD) is vital to ensure the continuity of identity services during failures, cyberattacks, or unforeseen disasters. Below is a structured approach to building a resilient disaster recovery strategy. Solution: Disaster Recovery Planning Define Objectives and Scope Recovery Time Objective (RTO):...
How to track failed logon attempts in Active Directory
Track failed logon KB ID 0001209 Problem If a large number of failed logon attempts occur within a certain period of time, it could be an indication of a security threat, which is why it is important that organisations have a proactive means of auditing and monitoring whenever this happens. There are a number of ways you can perform this audit, one of which is using the native tools. Here, we will take you through the steps so that...
Windows Server – Enable LDAPS
KB ID 0000962 Problem Note: Starting with Windows Server 2019, LDAPS (LDAP over SSL/TLS) is enabled by default, assuming a Server Authentication certificate is installed on the Domain Controller. Active Directory is built on LDAP, I’ve known this for a long time, but other than it’s a directory protocol that’s about all I did know. Like any directory, if you want information when you query the directory it returns a...
Cannot Join Domain?
Cannot Join Domain KB ID 0000534 Problem The primary cause (99.99% of the time) a client cannot connect to, or join a domain is DNS related. The specified domain either does not exist or could not be contacted Solution : Cannot Join Domain 1. To Troubleshoot you need to know the IP address of your DNS server, In many cases it’s on the first domain controller but that’s not always the case so find out (go to a WORKING...