Auteur archief:leodegroot

November 2022 security update kills Kerberos AES usage

On November 8th 2022, Microsoft released a number of updates in the monthly patches.Several issues in Kerberos should be fixed, but the update also creates issues with Kerberos in some circumstances. The update including the issue mentioned below is KB5019964 (server 2016) and potentially KB5020023/KB5020010(2012 R2), KB5019966 (server 2019), KB5019081 (server 2022). I left outMeer lezen over “November 2022 security update kills Kerberos AES usage”

Hyper-V VM start and move issues after system recovery

Recently I was attempting to replace the operating disk in one of my Hyper-V hosts in my home datacenter. During that operation, I intended to migrate from a rather small SSD drive, to a mirrored set of 1 TB SATA SSD drives left over from an older storage server. My guess was I could easilyMeer lezen over “Hyper-V VM start and move issues after system recovery”

Explorer thumbnail view disabled after running OSOT

When you use VMware view for providing VDI desktops, you probably use the VMware OS Optimization Tool (OSOT) to improve the performance of the desktop. This tool takes quite some shortcuts in optimizing, blocking a lot of basic functionality which you might find handy. Most things can be re-enabled quite easily, but recently I’ve runMeer lezen over “Explorer thumbnail view disabled after running OSOT”

ADFS authentication using UserPrincipalName failing in multi-domain setup

This article is related to the Exchange Online migration article I recently posted. The customer involved uses several Windows domains. For this situation, two domains are relevant. The primary domain is connected to Office 365 using an Azure AD Connect server. The second domain is also populated to Office 365 using the same AADC server.Meer lezen over “ADFS authentication using UserPrincipalName failing in multi-domain setup”

Windows 10 performance problem

Recently, in a small customer setup, I’ve experienced very poor performance on new HP computer hardware. This customer used 6 new HP computers, connected to a small scale Office365 tenant. Users logon to their computers by using their Microsoft account. As an anti-malware product, Trend Micro Worry Free Business Security Services with Cloud App SecurityMeer lezen over “Windows 10 performance problem”

Migrating Exchange to Exchange Online in the Enterprise, what breaks and how to fix it

This article is based on a migration project I’m currently working on for a large financial company in the Netherlands. In total, we had to migrate around 10000 mailboxes. Because we wanted to keep effects for the users a minimum, I’ve written a migration script that fixes all functionality that gets broken by default whenMeer lezen over “Migrating Exchange to Exchange Online in the Enterprise, what breaks and how to fix it”

Domain controller unreachable with RDP

First real tech blog post. This is a situation many of you have experienced in the last couple of years. You used to be able to connect to a server using RDP, in many cases a domain controller, but suddenly, that server can no longer be reached, but you did not change anything on theMeer lezen over “Domain controller unreachable with RDP”