Vincent Bernat

With the team @free1337.bsky.social, we have developed a Netflow/IPFIX collector and visualizer. It is available at github.com/akvorado/akv.... It relies on several opensource components: GoFlow2, Kafka, ClickHouse, Vue, Tailwind, and more!

SimCity for ISPs: seriesoftub.es

New release of Akvorado, an IPFIX/sFlow collector and visualizer. Among the new features are support for TCP/SCTP for IPFIX, buttons to reverse direction in the console, timezone support, optional separate smaller inlet binary. Fetch it while this is hot! github.com/akvorado/akv...

btw you can try github.com/stepbrobd/ce... plugin to get a shared storage location for all certs (and other parts that uses caddy certmagic storage backend) i forked the og repo and added proper locking mechanism during cert renewal

I am annoyed since a long time of the default sort of GitHub for PR and issues. I would like "last updated" to be the default. Amazing this is not user-configurable... github.com/orgs/communi...

To make SVG rendering more reproducible for my blog, I now normalize the fonts (serif to Literata, sans-serif to Source Sans Pro, monospace to Iosevka) and embed the appropriate subset in each SVG. +30% in size, but this was long term issue I had and it's still far smaller than raster to WebP (5×).

Link checking to avoid link rot is now increasingly hard. A lot of sites are now returning errors, whatever if you lie or not about the user agent. For example Cilium documentation returns a 429 (with Retry-After: None), while it's a static site.

New release of Akvorado! github.com/akvorado/akv....

Self-hosted HTTP tunnels with SSH and nginx: vincent.bernat.ch/en/blog/2026.... That's like ngrok or Cloudflare Quick Tunnels, but self-hosted and you only need SSH.

From twitter bad_pote

Bot-free self-hosted analytics with GoatCounter on NixOS: vincent.bernat.ch/en/blog/2026.... With an alternative JavaScript client, a fallback to CSS, an overdoing local proxy, and a lot of NixOS, including Litestream to backup an SQLite database!

Quality of life in Thunderbird with this patch to avoid drag&drop folders by accident: github.com/vincentberna.... Thanks to Nix, it's no issue to apply such a patch.

Sidenotes with CSS anchor positioning: vincent.bernat.ch/en/blog/2026.... A short post about positioning notes in the margin (and not at the end of the document) and a digression on how to spend far more time than needed on this issue.

It's difficult to build very high performance tools in Go. For example, BART would benefit for an helper over net/netip: github.com/golang/go/is.... Unfortunately, the maintainers consistently reject these APIs but Go don't really offer any safe workaround. You can't extend, you can't fork.

Minor update for Akvorado, your beloved flow collector. Among them, a few small fixes, the ability to zoom out, or the support for DB-IP. github.com/akvorado/akv...

An interactive introduction to the spanning tree protocol: vincent.bernat.ch/en/blog/2026.... While the spanning tree protocol is quite old, it is still sometimes useful. This article explores it with interactive demonstrations running a real daemon (MSTPD) compiled to WebAssembly with Emscripten.

Wow, FVWM is coming to Wayland! codeberg.org/thomasadam/cow!

nixpkgs multiverse, now faster and leaner! fzakaria.com/2026/08/14/n... With the previous iteration released last week, if you pin a lot of packages, you pull many versions of nixpkgs and evaluate them. Not anymore! You can fetch directly from the cache! Look at the other articles from the blog too

In Debian, CDBS has been deprecated and removed. It didn't get much love, but for a very long time, it made packaging easier by making implicit good decisions, a bit like the "recent" dh command sequencer (2008).

New release of Akvorado, a IPFIX/sFlow collector with a builtin web interface for visualization. We are switching to CalVer for versioning. The GeoIP/networks database migrates from the orchestrator to the outlet. It is now possible to export enriched flows to Kafka. github.com/akvorado/akv...

came across a neat post to understand IP lookup using trie and other optimizations on top of it. thanks @vincent.bernat.ch vincent.bernat.ch/en/blog/2017...

I was about to write an article comparing semicolons in English with BGP confederations in networking: both of them are taught in class but shouldn't be used outside. Unfortunately, it seems the discourse around semicolons is more nuanced.

I've asked IEEE the authorization to reproduce one diagram from IEEE 802.1Q (through standards.ieee.org/ipr/copyrigh...). Do they answer "fast"?

I had this article about contributing to RRDtool in draft for more than 10 years! I just published it "as is:" vincent.bernat.ch/en/blog/2013... The goal was to encourage people around me to contribute to open source. Unfortunately, the patch took a bit of time to be accepted.

Just published Akvorado 2.4.1, your friendly IPFIX/NetFlow/sFlow collector: github.com/akvorado/akv....

In Firefox, one tab for Outlook Web and one tab for Teams already eats 2.1GB of RAM. The next one is Zulip with only 150MB (which I think is OK).

ah yes...I should also post about OUR book. the 2nd edition of "Observability Engineering" is now available for download.. and you can download it for free on the honeycomb site. this was supposed to be an update, and ended up being a total rewrite (& then some). 😅 www.honeycomb.io/blog/the-sec...

I've made a Kubernetes that runs in the browser, and today we're open sourcing it. The hope here is to make super interactive and visual web content about Kubernetes much easier to write, and we have a whole bunch planned this year. Repo: github.com/ngrok/webern... Demo: webernetes-demo.ngrok.app

(Some) writers appreciate LLM writing assistance but readers hate it. Survey says… writethatblog.substack.com/p/dev-reacti... If readers suspect AI, they not only stop reading, but also downvote/avoid the author.

Building a Soviet Nail Factory: how KPIs killed efficiency. A story that I often tell. It is now old enough to not upset my former colleagues. vincent.bernat.ch/en/blog/2026...

TIL: `export -f` in bash can export a function to a subshell

yes!! thank you for noticing!! :D i have been going to TOWN lately generating sticker art and slogans and learning graphic design fundamentals. maybe i will write about that today, hm. this is one of my favorite themes.. it feels very.. scandinavian? i will mail you some if you give me an address!

Blogging with an LLM assistant: vincent.bernat.ch/en/blog/2026... (grammar, copyediting, translation). This specific post is *not* modified by an LLM.

i wrote a post about the growing divide between AI skeptics and AI enthusiasts. wins and costs are both real, but too often fall on different groups of people. when you're only experiencing half the story, it's too easy to write each other off. charitydotwtf.substack.com/p/ai-enthusi...

New release of Akvorado (direct from the train to Montpellier): github.com/akvorado/akv.... There is a new bidirectional option for Sankey graphs. Also, some improvements on handling the RIB. The next version is likely to ship an architecture change to pave the way to more flexible flow enrichment.

More and more people I deeply respect and have learned a lot from over the years feel like they are speaking into a void, to the point where they are losing motivation to continue making content, which got me to write my first post on my site in over a year... www.kevinpowell.co/article/tell...

Scaling Akvorado BMP RIB with sharding. Making an efficient RIB to store 10M+ routes is challenging. While writing this article, I discovered additional optimizations. That's one reason to blog! vincent.bernat.ch/en/blog/2026...

I didn't notice until recently, but Epiphany, the GNOME browser, is quite on par with Safari. Same rendering engine, same JS engine, almost the same UI. It's convenient to test "Safari" on Linux.

Don't upgrade Docker Engine to 29.5.0 if you are using Akvorado. It breaks the conntrack handling. See here for some details: github.com/akvorado/akv... 😭