Category: worth reading

Dmytro Shypovalov wrote a fantastic article explaining the basics of MPLS-based Segment Routing. It’s pretty much equivalent to everything I ever wrote about SR-MPLS but in a much nicer package. Definitely a must-read.

Here’s another AI rant to spice your summer: AI Is Still a Delusion, including an excellent example of how the latest LLMs flunk simple logical reasoning. I particularly liked this one-line summary:

The real danger today is not that computers are smarter than us but that we think computers are smarter than us and consequently trust them to make decisions they should not be trusted to make.

It might be worth remembering that quote when an AI-powered management appliance messes up your network because of a false positive ;)

In Matt Duggan’s blog post, you’ll find a scathing review of another attempt to throw AI spaghetti at the wall to see if they stick: the GitHub Copilot Workspace.

He also succinctly summarized everything I ever wanted to say about the idea of using AI tools to generate networking configurations:

Having a tool that makes stuff that looks right but ends up broken is worse than not having the tool at all.

Daniel Dib went on another deep dive: Why Do We Have Native VLANs? What I loved most was that he went through the whole 802.1 standard (quite an undertaking) and explained the reasoning that VLAN-aware switches behave the way they do.

You should also read the follow-up post: what happens if a VLAN-unaware switch receives an 802.1Q-tagged frame?

In another wonderful deep dive, Julia Evans explains why you can’t edit the command line in some Linux utilities like the ancient sh.

You’ll also figure out:

• Why does CTRL-A jump to the beginning of the line?
• How can you enable command line editing in ancient utilities?

Have fun!

Bogdan Golab sent me a link to an (open access) article in Ethics and Information Technology arguing why ChatGPT is bullshit. Straight from the introduction:

Because these programs cannot themselves be concerned with truth, and because they are designed to produce text that looks truth-apt without any actual concern for truth, it seems appropriate to call their outputs bullshit.

Have fun!

Sharada Yeluri published an interesting overview of the evolution of network security, from packet filtering firewalls to GenAI and Quantum Computing (yeah, she works for a networking vendor ;). Definitely worth reading if you’re looking for an intro-level overview.

Some people insist on using Excel as the ultimate source of user-supplied data (including network automation source of truth).

If you agree with me that that’s not necessarily the best idea out there, you might enjoy this rant by Nikhil Suresh.

Here’s another rant to spice up your weekend: focus on fixing your company’s problems instead of chanting the AI mantra. Have fun ;)

Dan Massameno wrote a series of blog posts describing the challenges you might encounter when connecting Internet-of-Things¹ devices to a Cisco SD-Access network. It is an absolute must-read if you have to deal with IoT devices.

Marc Brooker published an interesting blog post arguing that we need distributed systems for more than just scale.

Keep that in mind the next time someone tries to sell you the beauties of a centralized control plane – an idea that should be dead by now regardless of what ONF keeps preaching but will inevitably reappear in some form or other due to RFC 1925 Rule 11.

A year or two after Damien Garros told me that “he moved to France and is working on something new” we can admire the results: Infrahub, a version-control-based system that includes a data store and a repository of all source code you use in your network automation environment. Or, straight from the GitHub repository,

A central hub to manage the data, templates and playbooks that powers your infrastructure by combining the version control and branch management capabilities of Git with the flexible data model and UI of a graph database.

I’ve seen an early demo, and it looks highly promising and absolutely worth exploring. Have fun ;)

I mostly gave up on LLMs being any help (apart from generating copious amounts of bullshit), but I still thought that generating summaries might be an interesting use case. I was wrong.

As Gerben Wierda explains in his recent “When ChatGPT summarises, it actually does nothing of the kind” blog post, you have to understand a text if you want to generate a useful summary, and that’s not what LLMs do. They can generate a shorter version of the text, which might not focus on the significant bits.

Tom Limoncelli wrote another must-read masterpiece: sometimes you’ll save time if you make two trips instead of one.

The same lesson applies to network design: cramming too many features into a single device will inevitably result in complex, hard-to-understand configurations and weird bugs. Sometimes, it’s cheaper to split the required functionality across multiple devices.

AWS started charging for public IPv4 addresses a few months ago, supposedly to encourage users to move to IPv6. As it turns out, you need public IPv4 addresses (or a private link) to access many AWS services, clearly demonstrating that it’s just another way of fleecing the sheep Hotel California tax. I’m so glad I moved my videos to Cloudflare ;)

For more details, read AWS: Egress Traffic and Using AWS Services via IPv6 (rendered in beautiful, easy-to-read teletype font).