Exchange 2016/2019 – convert a mailbox to a shared mailbox

In this tutorial, I will explain how to convert a “normal” mailbox into a shared mailbox. The main difference between a user mailbox and a shared mailbox is that the latter is linked to an Active Directory user account which is deactivated, therefore more “secure”. The other interest is that these mailboxes do not need …

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PowerShell: show the contents of a text file

In this tutorial, I will show you how to display the contents of a text file (txt, yaml, php, vbs…) in a PowerShell window. In fact, it’s very simple, just use the Cmdlet Get-Content and specify the file name. Which give : If you are familiar with the cat command in Linux, you can also …

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Crowdsec: send logs to Elasticsearch (ELK)

In this tutorial, I will explain how to send decision logs to Elasticsearch (ELK) so that you can create a dashboard to use the logs. What you need to achieve what described in the tutorial: Crowdsec version 1.2.x or higher an Elasticsearch server or an ELK stack Since version 1.2 of Crowdsec, a notification system …

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ncdu: analyze disk space in command line on Linux

In this “‘little” tutorial, I will explain how to view and analyze the space in the command line on Linux with ncdu. If you are adapted from WinDirStat or TreeSize on Windows, the ncdu utility on Linux allows you to have the “same” thing in a terminal. The first thing to do is to install …

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Exchange: optimize database space

In this tutorial, I will explain how to optimize the disk space used by the databases (MailboxDatabase) of Exchange. What you need to know is that the size of Exchange databases only increases and over time, “empty” spaces are created in the database files. Empty space is normally reused to store other data. Despite this …

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Disable server manager at logon

If you’re used to connecting to Windows servers, you may have noticed that Server Manager opens every time, although handy, this tends to “slow” the login and is intrusive especially when you don’t need it. I will explain how to disable its automatic opening. If you have already closed it, open the server manager. Click …

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PFX certificate: extract the certificate and the private key

In this tutorial, I will explain how to extract the certificate and the private key from a certificate in PFX format with OpenSSL. The easiest way to use OpenSSL is to use a Linux computer. 1. Copy the PFX file to your computer where OpenSSL is installed. 2. The first step will be to extract …

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Ubuntu: show default gateway

Here is how to display the default gateway on Ubuntu from the command line. Ubuntu 20.04 + (without net tools) Ubuntu 18.04 – (with net-tools)

PrintNightmare: secure print configuration

In this “little” tutorial, I will show you how to set up a “secure” configuration. Since the publication of the PrintNightmare flaw, Microsoft has deployed several updates to correct this problem and took the opportunity to modify the behavior of Windows to harden the configuration. In this tutorial, we will see the parameters to use …

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