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Zabbix Summit 2022 in Riga: Keeping hundreds of Windows Zabbix agents in sync across different customers

I’m happy to announce that I’ll be one of the speakers at Zabbix Summit 2022 in Riga. As moderator of the Zabbix Telegram and Zabbix reddit community, I was asked by Zabbix to present at the premier event about Zabbix monitoring.

The 10th Zabbix Summit is taking place in Riga, Latvia on October 7-8. My speech is titled:

Keeping hundreds of Windows Zabbix agents in sync across different customers

As a Managed Services Provider (MSP) we are responsible for dozens of customers, with hundreds of Windows Servers. Therefore, we introduced mechanisms to automatically deploy, configure, and sync Windows Zabbix agents across all these isolated environments. In this process, we leverage a tool set consisting of Azure DevOps, Git, PowerShell, and a publicly available Zabbix agent auto-updater, to provide all our customers’ servers with the latest Zabbix agent configuration possible.

Marco Hofmann is an IT-Systems Engineer with 15+ years worth of experience. He works at the german Managed Services Provider ANAXCO GmbH. His priority is the configuration and maintenance of the company’s central Zabbix environment, which is a key component in the fulfillment of the customers’ maintenance contracts. He also focuses on designing and configuring Citrix RDSH environments, fully automated with PowerShell.

Zabbix Telegram Community: https://t.me/ZabbixTech

Zabbix reddit Community: https://www.reddit.com/r/zabbix/

Zabbix website: http://www.zabbix.com/

All speeches from Zabbix Summit will be recorded and uploaded a few weeks later.

Update Citrix Workspace Environment Management (WEM) to 2106 (2106.1.0.1)

An update guide for Citrix Workspace Environment Management (WEM) to the latest version 2106.

On June 16, 2021 Citrix released version 2106 of Workspace Environment Management (WEM). This is an update guide.
Customer Success Services / Software Maintenance eligibility date: May 15, 2021

Download Citrix WEM 2106 (2106.1.0.1) here:
https://www.citrix.com/de-de/downloads/citrix-virtual-apps-and-desktops/components/workspace-environment-management-2106.html

What’s new:
https://docs.citrix.com/en-us/workspace-environment-management/current-release/whats-new.html

Fixed issues:
https://docs.citrix.com/en-us/workspace-environment-management/current-release/fixed-issues.html

WEM setup files
WEM setup files

Continue reading “Update Citrix Workspace Environment Management (WEM) to 2106 (2106.1.0.1)”

Potentially ongoing worldwide UDP:443 (EDT) DDoS amplify attack against Citrix (NetScaler) Gateway

Since 19 December 2020 7pm CET we see a possible worldwide DDOS amplify attack against Citrix Gateway UDP:443 DTLS EDT services.

Changelog

  • 11.01.2021: Added information about the new Citrix ADC Gateway (formerly NetScaler) firmware releases, which solve the memory leak issue with -helloVerifiyRequest
  • 24.12.2020: Added information about the official Citrix Knowledge Center article CTX289674
    Added a final summary, that repeats all possible solutions
    Maked it a lot clearer, that -helloVerifiyRequest doesn’t seem to work well
  • 22.12.2020: Added a warning note, that -helloVerifiyRequest doesn’t work on all Citrix ADC (NetScaler) firmware versions
  • 21.12.2020: Added a third possible solution regarding -helloVerifiyRequest
  • 21.12.2020: Initial version

The situation

During the night from Saturday (19.12.2020) to Sunday (20.12.2020) our Zabbix Monitoring informed us, that several Citrix Gateway VPX (50) appliances were at its license cap. We investigated the situation and soon found out, that we had 0 ICA sessions on most of them, hence no explanation for the traffic.

Zabbix Citrix Gateway Throughput Monitoring Graph
Zabbix Citrix Gateway Throughput Monitoring Graph

Continue reading “Potentially ongoing worldwide UDP:443 (EDT) DDoS amplify attack against Citrix (NetScaler) Gateway”

Caution: FSLogix 2009 (2.9.7621.30127) profiles won’t logoff completely

At three customer sites I created test machine catalogs with FSLogix 2009, and all of them had the same issue, that FSLogix profiles won’t logoff completely at the end of the day.

Update January 11, 2021: I was informed about a better solution via Twitter, and updated the Blog post accordingly.

The Problem

During my personal tests with FSLogix 2009 (2.9.7621.30127) I discovered that the profiles won’t logoff completely at the end of the day. See the following screenshots.

Hanging profiles (1)
Hanging profiles (2)

You can clearly see, that despite there are no active or disconnected user sessions, some of the VHDX disks are still mounted, but more important the folders from C:\users\ won’t vanish.

This makes a second login impossible on the same VDA.

Download and install latest Office 365 via Office Deployment Tool (ODT)

Inspired by Trond Eric Haavarstein’s evergreen PowerShell setup scripts, I created a download and install script for Office 365 Deployment Tool (ODT).

Microsoft Office 365 is the new standard in the EUC space right now. To honor this, we need a fast and reliable way to install it with our favorite deployment tools like MDT or PDQ,  for example when you rebuild your master images.

There are a few different ways to deploy Office 365, but they are all similar:

  • You need the Office 365 Click-to-run setup.exe (Office Deployment Tool (ODT))
  • You need a XML configuration file
  • You decide to deploy from a pre-build offline cache or the files are downloaded from Microsoft each and every time

And then you go: setup.exe /configure configuration.xml

Pretty straight forward you think, but non the less I had problems with this approach. And this is due to the fact, that the Office Deployment Tool itself gets updated pretty often. And this breaks your unattended deployments sooner or later, as the setup.exe stops working. Continue reading “Download and install latest Office 365 via Office Deployment Tool (ODT)”