Michael Boelen

Founder of CISOfy; author of #infosec tools rkhunter and Lynis; involved with NLUUG, #openstandards and #opensource; helping companies to secure their #Linux environment; interested in #sustainability and sharing messages in English, sometimes in Dutch 🇳🇱. My Dutch-only account is also Michael Boelen (npub1grf…rfed) (mastodon.nl).

Personal website: https://michaelboelen.com/
Linux security blog: https://linux-audit.com/
Linux Lorem: https://linuxlorem.com/

Public Key

npub1grfgr7uxckl7nya5tfhmmg0nsxw586ynz83fvr9etjs96kvxwwfqd3rfed

NIP-05 Address

mboelen_at_mastodon.social@momostr.pink

Profile Code

nprofile1qqsyp55plwrvt0lfjw695maa58ecr82razf3rc5kpju4egzatxr88yspz3mhxue69uhhyetvv9ujuerpd46hxtnfduqs6amnwvaz7tmwdaejumr0dswewq3g

Publishing to

relay.snort.social

nos.lol

relay.damus.io

Author Public Key

npub1grfgr7uxckl7nya5tfhmmg0nsxw586ynz83fvr9etjs96kvxwwfqd3rfed

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Last Notes

2026-05-25 08:20:18 UTC

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Great tips and most of that I already had in my draft. I wanted to go for unbound as I am familiar with it. But I saw that unwind does a great job as well. As it also configures your resolv.conf, it looks to be a nice combination.
I will soon share my draft document with you, so you can shoot at it 😄

2026-05-25 07:53:07 UTC

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Sounds good. There will be differences due to the OS, but I guess there remains some overlap in software components.

2026-05-24 22:31:10 UTC

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Yes, it will. When things are ready, I will share configurations and full instructions with all steps. Love to compare things and see if I missed anything.

2026-05-24 15:03:18 UTC

Any of my followers interested in running a mail server with #OpenBSD 🐡 and want to help testing?
Working on the setup and documenting it along the way. So curious to learn if someone wants to tag along or test it.
#selfhosting #digitalautonomy #mailserver #email

2026-02-02 18:39:26 UTC

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Pun intended? Hunting, sea, you 🦈 😄

2026-02-02 18:08:30 UTC

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Man, so many interesting things to read now. Thanks for mentioning me, even though I don't know yet where 😆
@npub1cd4…ce7a @npub16f3…6xc0 @npub10sj…sg03 @npub1ruv…702v @npub1p6n…xcze @npub17a6…mgkf @npub1xsv…2855 @npub1kqc…7wgd [@autonomic](https://sunbeam.city/@autonomic ) @npub105p…6k4j [@adam_caudill](https://infosec.exchange/@adam_caudill ) @npub1wfp…w2m9 @npub14u6…4fht @npub1zav…tuty [@brennan](https://social.lol/@brennan ) @npub1ruj…sejm @npub1wee…9r06 [@sphakos](https://toot.cat/@sphakos ) @npub1p24…k89p [@ravachol](https://mastoart.social/@ravachol ) @npub1p5e…02lu @npub1qmt…qzxr @npub1dwl…7mp0

2026-02-02 08:44:55 UTC

You might want to be careful with filling in all your #LinkedIn details.
I can imagine that checking [Civil Rights and Social Action] or [Human Rights] might be troublesome if you are looking for a job in the USA (and some companies with their stance against unions).
Rediscovering things now I'm leaving the platform: https://michaelboelen.com/blog/moving-away-from-linkedin-step-by-step/
#BigTech
https://files.mastodon.social/media_attachments/files/116/000/145/700/788/998/original/713d7e2fc389763d.png

2025-12-05 06:40:10 UTC

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Usually 4 or 8 GB. F12 or ESC is a common key to select the boot device.

2025-11-28 15:09:15 UTC

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Sounds like Sharepoint for code 😆

2025-11-22 23:23:44 UTC

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Same when you plug in controller 2 in port 1? Might rule out a weak connection to one of the pins.

2025-11-21 08:28:47 UTC

My #systemd presentations slides (80+) for the @npub1zcu…k0sa conference are now available.
https://michaelboelen.com/presentations/
The original abstract: https://nluug.nl/evenementen/nluug/najaarsconferentie-2025/talks/michael-boelen-linux-speedrun-systemd/
Got suggestions or good additions, love to hear!
A few asked if there is a recording. The answer is probably yes, but it is in Dutch (and may take a while to be published). But... there will be videos soon that I record myself about this topic via Linux Lorem.

2025-10-27 09:24:57 UTC

I am planning on creating a video channel about #Linux named Linux Lorem (https://linuxlorem.com/). Now #PeerTube came up a few times. So that raises a few questions, including on how to use it in the future.
Now the big question for you: How often do you watch videos on PeerTube 📽️?
Would appreciate a boost 🚀 to get as many people responding and get a better picture.

2025-07-30 16:13:34 UTC

Lynis, the security scan tool for BSD/Linux/Unix systems has a new version: 3.1.5!
More updates and changes are coming.
Do you like #OpenSource? Consider contributing in any way that you can. If you are working for a company, consider the Enterprise version to support the work on this #FOSS tool.

2025-03-07 12:00:27 UTC

I use @npub1rk6…hv4q and really want to like it, but every action feels so slow. Not fully sure why that is. The PHP stack, too much hooks for plugins/checks/thumbnails?
#Nextcloud

2025-02-03 09:11:06 UTC

Are you #dyslexic? Recently learned about the OpenDyslexic font: https://opendyslexic.org/
You can use this as your default font, to make texts easier to read for you. For example, in Firefox you can switch the default font and disable custom fonts that websites use.
#accessibility

2025-01-27 17:01:59 UTC

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Yes, will definitely add them. They must be somewhere on the queue list to add. Thanks!
@npub1l78…m0ct

2025-01-27 13:41:55 UTC

Added a new entry to the RSS list: It's FOSS
The website of It's FOSS covers a wide range of topics with Linux and open source software. It's a great resource to learn about new software and ongoing developments within the subject area.
Full list: https://linux-audit.com/resources/linux-rss-feeds/
Follow: @npub1em3…3u4v
Let's grow #RSS again and share your #RSSFeed

2025-01-11 00:08:55 UTC

Any followers using #nixos as a public facing webserver? How do you perform auto-upgrades?
#linuxsecurity

2025-01-10 09:50:16 UTC

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Why is Fedora or Gnome unusable for you?

2025-01-05 23:01:59 UTC

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Bij het gebruik van spaties in bestandsnamen is het gebruik van quotes vaak aan te raden of zelfs nodig. Of als we andersom redeneren: gebruik geen spaties in bestandsnamen als het niet nodig is. Uiteraard ligt dat sterk aan type bestand. Bij een document met een langere titel is dat lastig, bij een "to do" lijst kan dat eenvoudig als todo.txt.
@npub130l…6x8t

2025-01-05 18:40:57 UTC

Added a whole bunch of descriptions from the queued list of #linux commands.
The list is growing quickly, now passed the 200!
https://linux-audit.com/system-administration/commands/
I enjoy researching these commands, as there are some golden nuggets in them. Example: you have a problem with file permissions, but don't know where in the path structure it happens. Go to a directory, then run: namei -l $(pwd)
This shows you from the root up to your directory the permissions. Awesome!

2025-01-05 11:01:23 UTC

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This is why I have rate-limits configured in nginx. After you hit the rate-limit and don't back down (and keep causing HTTP/429), you get a lovely auto-block.
I also block all requests without the Accept-Encoding header.
When it comes to bandwidth, it is too easy to waste resources of others 😕
If you are using nginx and need some snippets, let me know.

2025-01-01 19:44:55 UTC

If you are like me, you might have peeked at most of the files under /proc, just to see what kind of information is in them. Recently looking at the #Linux scheduler, so I revisited the 'sched' file (/proc/PID/sched).
Well, I have difficulties finding a good overview of the values (and explanation!). So you might have guessed it.. a new article is born.
https://linux-audit.com/kernel/scheduler/explanation-of-values-in-proc-pid-sched/
Work in progress, so feedback, thoughts, boosts very welcome 🚀 . Let's complete this thing!
#blog

2024-12-22 09:37:17 UTC

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No thank you 😇

2024-12-16 16:04:32 UTC

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Wow.. Thanks Mike.
But... with so many blogs, where to start? 😇

2024-12-16 13:34:41 UTC

Lately I got a some new followers, so let me introduce myself again: Dutch citizen interested in Unix, #Linux and #infosec, in particular the combination. Was the original author of rkhunter, a #malware detector, nowadays doing primarily #Lynis development, an #auditing tool that is #FOSS. I share my knowledge as much as possible, as I believe there this will benefit us all. My primary channel is my #blog (see bio) and with a copy to here.
Got questions? Happy to answer them.
#introduction

2024-12-15 23:14:37 UTC

Are you still using #RSS?
Since updating my blog, I actually started adding more feeds to my reader again. Also to test if my own feed is working 😄
Any good suggestions for feeds about #linux #devops #linuxsecurity or #foss?
Link to my feed: https://linux-audit.com/feed/

2024-12-12 22:55:37 UTC

Along the way I'm tagging more blog posts with system calls and add a short description to them. Why not put them into an overview for easy access, right?
https://linux-audit.com/kernel/syscalls/
Hope it helps others to better understand what syscalls do, as they are many of them. Getting them know them one by one also helps understanding the #Linux kernel a bit better, even if you aren't a kernel developer.

2024-12-07 22:47:31 UTC

Using #nginx and #systemd on a system is more common nowadays. Did you already check out this #linuxsecurity hardening profile for nginx?
https://linux-audit.com/systemd/hardening-profiles/nginx/
It's a set of parameters that sandbox nginx. The best part of implementing is that you really start to learn what a process does or does not need very quickly. Good for your #linux knowledge 💪
Also interesting, unit settings: https://linux-audit.com/systemd/settings/units/
If you implemented the profile, love to hear how you like it! Anything missing?