Today I faced an interesting problem. A customer told me that their Exchange 2010, which is currently part of a Exchange cross-forest migration project, has an issue with Outlook Web Access and the Exchange Control Panel. Both web sites fail with a white screen and a single message:
440 Login Timeout
I checked some basics, like certificate, configuration of the virtual directories and I found nothing suspicious. Most hints on the internet pointed towards problems with the IUSR_servername user, which is not used with IIS 7 and later. But authentication configuration and filesystem permissions were okay.… Read more
As part of a Office 365 tenant rebuild, I had to move a custom domain to the new Office 365 tenant. The old tenant was not needed anymore, and the customer had to move to a Non-Profit tenant for compliance reasons. So the migration itself was no big deal:
disable AzureAD sync
change UPN of all users
remove the domain
connect the domain to the new tenant
setup a new AzureAD sync
time for a beer
That was my, honestly, naive plan for this migration.
Disabling the AzureAD sync was easy. Even the change from ADFS to Password Hash Sync was easy. Changing the UPN for all users was a bit challenging, but the PowerSHell code in this article was quite helpful.… Read more
While debugging a vCener Lifecycle Manager, which was unable to download updates, I’ve stumbled over a weird behaviour, which is (IMHO) by design.
Some of you might use a proxy server. And some of you might use a proxy server which requires credentials. In my case, my customer uses a Sophos SG appliance as a web proxy server with authentication. The customer creaded a user with a complex password. But I was unable to get a working internet connection.
I played a bit with curl on the bash of the vCenter.… Read more
Its been four month since my last blog post, and the blog frequency was quite low before that. This blog is, to be honest, a giant pile of stuff that has not worked as expected. Okay, some random thoughts or howto’s, but most blog posts are about stuff that failed in some way. That’s a bit “depressing”. I should write more about the fun things in my life
For a pretty long time my focus was on infrastructure. And my focus _is_ on infrastrucutre – Networks, lots of storage, virtualization with VMware. And always full stack: Networking, Storage, Servers, Operating System, always with a little focus here and there.… Read more
Adding a second factor to your authentication is always a good idea. Typically the second factor is a One-Time Password (OTP) or a push notification. But what if you want to allow the login into your Horizon View environment only from specific devices? This implies that you need some kind of second factore that also identifies the device. At this point the arch enemy of many of us comes into play: Certificates!
To be honest: It is not so hard to get client device certificate authentication to work. All you need is:
Unified Access Gateway 2.6 or later
Horizon 7 version 7.5 or later
A certificate installed on the client device that Unified Access Gateway accepts
Configure X.509 authentication settings
The first step is to configure the UAG to accept a device certificate.… Read more
Today I had to deploy a new vCenter appliance. Nothing fancy, new deployment. Stage 1 was easy, but stage 2 failed several times. I re-deployed the vCenter appliance two times, but as the deployment failed for the third time, I took a look into the logs.
The deployment failed without any error, but it didn’t finished. It stopped during the start of different services without any error.
First of all: Log into the appliance using SSH or the console. Use the root account and the root password you have entered during the setup.
A good point to start are the logs under /var/log/firstboot. I used ls -lt to get the last written logs.… Read more
One of my customers replaced the old Veeam environment with new gear. The HW was pretty simple designed:
two HPE ProLiant
per server two HPE D3610 enclosures with 6 TB disks
~ 5km between backup server and backup copy destination
One server was designed to act as the Veeam backup server and repository, and the second server was designed to act as the backup copy destination. Both servers were running Windows Server 2019 Standard. We planned to use Windows Deduplication and ReFS, but it turned out that we have to adjust the filesystem size to get Windows Dedup working. Windows Dedup supports filesystems up to 64 TB.… Read more
Yesterday, I passed the first exam of the year. In this case the WatchGuards Network Security Essentials exam. The exam covers basic networking and firewalling skills, as well as the necessary knowledge to configure, manage, and monitor a WatchGuard Firebox. If you were familier with networking and firewalls in general, this exam is a “low hanging fruit”. I had to take it due to partner conditions.
WatchGuards offers a pretty good study guide for this exam which you can get for free.. The exam is delivered by Kryterion and can be taken in a test center or as online proctored exam.
The closed book exam consists of 70 questions.… Read more
This blog post covers objective 1.1 (Gather and analyze business requirements) of the VCAP-DCV Design 2021 exam. It is based on the VMware Certified Advanced Professional 6.5 in Data Center Virtualization Design (3V0-624) Exam Preparation Guide (last update December 2019).
When you get the task to design something , you will instinctively start gathering information about the requirements that have to be fulfilled. Everything IT is doing should support the business in some way.
The necessary skills and abilities are documented in the exam prep guide for the older VCAP6-DCV Design exam (3V0-622).… Read more
In August 2018 I’ve passed the VCAP6-DCV Deployment exam. After a busy first half of 2019 it’s time to start preparing the VMware Certified Advanced Professional — Data Center Virtualization Design 2019 exam. But I lost focus and in 2020 I had a lot to do – but not VMW related and so I also missed my goal to take the VCAP-DCV Design exam.
I have to push myself, so I decided to re-cap my half finished blog series to get myself back on track.
There are many great study guides out there, but in most cases I need “my own study guide” to feel well prepared. I hope this blog series will keep me on track, and I stay focused.… Read more
To change your privacy setting, e.g. granting or withdrawing consent, click here: