Exchange DAG member dies during snapshot creation

Yesterday, a customer called me and told me about a scary observation on one of his Exchange 2016 DAG (Database Availability Groups) nodes.

In preparation of a security check, my customer created a snapshot of a Exchange 2016 DAG node. This node is part of a two node Windows Server 2012 R2/ Exchange 2016 CU7 cluster.

That something went wrong was instantly clear, after the first alarm messages were received. My customer opened a console windows and saw, that the VM was booting.

What went wrong?

Nothing. Something worked as designed, except the fact, that the observed behaviour was not intended. read more

Exchange receive connector rejects incoming connections

As part of a bigger Microsoft Exchange migration, one of my customers moved the in- and outbound mailflow to a newly installed mail relay cluster. We modified MX records to move the mailflow to the new mail relay, because the customer also switched the ISP. While changing the MX records for ~40 domains, and therefore more and more mails received through the new mail relay cluster, we noticed events from MSExchangeTransport (event id 1021):

192.168.xxx.xxx is the mail relay cluster, which is used for the in- and outbound mailflow. read more

Stop using your work email for your Microsoft account

Microsoft two different logins for their services:

  • Microsoft Account (former Live ID)
  • work or school account (Azure AD)

Both are located in different directories. The Microsoft account is located in another user database at Microsoft, as a work or school account. Latter are located in a Azure AD, which is associated with a customer. Both account types are identified using the email address. Microsoft accounts are used for service like Skype, OneDrive, but also for the Microsoft Certified Professional portal. Work or school accounts are mainly used for Office 365 and Azure. read more

Citrix Certified Professional – Networking (CCP-N) exam experience

Last friday I passed the 1Y0-351 (Citrix NetScaler 10.5 Essentails and Networking) exam with a pretty good score. The exam was necessary, not only because I will do much more NetScaler projects in the future, but also because Citrix has made it mandatory to have a CCP-N in your company to to sell Citrix NetScaler.

Preparation

My employer booked me a 5-day course (CNS-220 Citrix NetScaler Essentials and Traffic Management). Very nice, although I already had experience with NetScaler deployments. This training was designed for NetScaler 12.0, not for 10.5. read more

Choose one, choose wisely – Office 365 tenant name

In the last months I came across several customers that were in the process to evaluate, or to deploy Office 365. It usually started with a Office 365 trial, that some of the IT guys started to play around with. Weeks or months later, during the proof-of-concept or during the final deployment, the customer had to choose a Office 365 tenant name. That is the part before .onmicrosoft.com.

I had it multiple times, that the desired tenant name was already taken. Bummer. But the customer wants to move on, so the customer decided to take another another name. For example, they added the post code to the name, or a random string. To their surprise, I put my veto on it. They immediately understood why, after I explained the importance of the tenant name. read more

Hell freezes over – VMware virtualization on Microsoft Azure

Update

On November 22, 2017, Ajay Patel (Senior Vice President, Product Development, Cloud Services, VMware) published a blog post in reaction to Microsofts announcement (VMware – The Platform of Choice in the Cloud). Especially these statements are interesting:

No VMware-certified partner names have been mentioned nor have any partners collaborated with VMware in engineering this offering. This offering has been developed independent of VMware, and is neither certified nor supported by VMware.

and

Microsoft recognizing the leadership position of VMware’s offering and exploring support for VMware on Azure as a superior and necessary solution for customers over Hyper-V or native Azure Stack environments is understandable but, we do not believe this approach will offer customers a good solution to their hybrid or multi-cloud future. read more

How to install Visual Studio Code on Linux Mint 18

I have wrote about the installation of PowerShell Core in Linux Mint 18 yesterday. Today, I want to show you, how to install Visual Studio Code on Linux Mint 18. The installation is really easy:

  1. Download the deb package
  2. Install the deb package
  3. Run Visual Studio Code

You can download the latest packages for Windows, Linux (deb and rpm, if you want even a tar ball), and Mac on the Visual Studio Code download page. Download the deb file. To install the package, open a Terminal window and run dpkg .

sudo  might ask you for a password. That’s it! Now you can simply start VS Code.After you have installed your favorite extensions, VS Code is ready to code. read more

How to install PowerShell Core on Linux Mint 18

Beside my Lenovo X250, which is my primary working machine, I’m using a HP ProBook 6450b. This was my primary working machine from 2010 until 2013. With a 128 GB SSD, 8 GB RAM and the Intel i5 M 450 CPU, it is still a pretty usable machine. I used it mainly during projects, when I needed a second laptop (or the PC Express card with the serial port…). It was running Windows 10, until I decided to try Linux MInt. I used Linux as my primary desktop OS more than a decade ago. It was quite productive, but especially with laptops, there were many things that does not worked out of the box. read more

Continuity vs. change

Note: I trashed this blog post several times. But I would like to express my point of view (hey, this is my blog. :D )

Some weeks back, I had an interesting discussion with a HR consultant. Bottom line: You ruin your career, if you stay for more than 3 years at the same company. IMHO this is bullshit.

I have started my IT career, right after school, with an apprenticeship at a local IT company. I finished this apprenticeship three years later, and my employer offered me a position as IT-Technician. Until 2004, I changed my employer three times. There were good reasons for each change. I learned pretty much in these years. The last change took me to my current employer. I have started as a Technical Consultant in October 2004. Today, thirteen years later, I’m leading the consulting and services business unit. There is a good chance I will not leave this company until retirement. At least not for the same or similar job role. read more

Notes about 802.1x and MAC authentication

Open network ports in offices, waiting rooms and entrance halls make me curious. Sometimes I  want to plugin a network cable, just to see if I get an IP address. I know many companies that does not care about network access control. Anybody can plugin any device to the network. When talking with customers about network access control, or port security, I often hear their complains about complexity. It’s too complex to implement, to hard to administrate. But it is not sooo complex. In the easiest setup (with mac authentication), you need a switch, that can act as authenticator, and a authentication server. But IEEE 802.1x is not much more complicated. read more