Category: worth reading

I encountered the Escape sequences (named after the first character in the sequence) while programming stuff that would look nicely on the venerable VT100 terminals (not to mention writing one or two VT100 emulators myself).

In the meantime, those sequences got standardized and (par for the course) extended with “proprietary” stuff everyone uses now. Julia Evans did a great job documenting the state of the art. Thanks a million!

You can use SR-MPLS, MPLS-TE, or an SDN controller to build virtual circuits (label-switched paths) across the network core. The controller can push the LSPs into network devices with PCEP, BGP-LU, or some sort of NETCONF/RESTCONF trickery.

Unfortunately, you’re only half done once you have installed the LSPs. You still have to persuade the network devices to use them. Welcome to the confusing world of traffic steering explored in the Loopback as a Service blog post by Dmytro Shypovalov.

I love good steamy rants, and The Generative AI Con from Edward Zitron is as good as they come. Pour yourself a glass of wine (or a cup of tea or whatever else you prefer) and have some fun ;)

Ole Troan, an excellent networking engineer working on IPv6 for decades, has decided to comment on the color of the IPv6 kettle, starting with:

• Is the transition to IPv6 inevitable? (hint: Betteridge’s law of headlines)
• The mistakes and missed opportunities in the design of IPv6 - episode 1 (aka Second System Effect¹)

I’m pretty sure Ole won’t stop there, so stay tuned.

Pavel Odintsov published a series of introductory blog posts describing protocols we can use to collect network traffic telemetry:

• Part 1 covers the ancient Netflow v5, Netflow v9, and IPFIX. It also mentions sampling and flow aggregation.
• Part 2 describes sFlow, port mirroring and sampled mirroring, and the use of IPFIX/Netflow v9 to transport mirrored traffic.

These blog posts will not make you an expert but will give you an excellent overview of the telemetry landscape¹.

Dmytro Shypovalov published another article well worth reading: why should you use an SDN controller for RSVP-TE. It covers:

• The reasons people might still prefer RSVP-TE over SR-MPLS and the current state of RSVP-TE
• What an SDN controller might bring to the RSVP-TE world
• SR/RSVP coexistence and interworking

Have fun!

Donatas Abraitis asked me to spread the word about the first ever Baltic NOG meeting in the second half of September 2025 (more details)

If you were looking for a nice excuse to visit that part of Europe (it’s been on my wish list for a very long time), this might be a perfect opportunity to do it 😎.

On a tangential topic of fascinating destinations 😉, there’s also ITNOG in Bologna (May 19th-20th, 2025), Autocon in Prague (May 26th-30th, 2025), and SWINOG in Bern (late June 2025).

The results of netlab integration tests are stored in YAML files, making it easy to track changes improvements with Git. However, once I added the time of test and netlab version to the test results, I could no longer use git diff to figure out which test results changed after a test run – everything changed.

For example, these are partial test results from the OSPFv2 tests:

Vini Motta decided to use AI on ipSpace.net content to find what it would recommend as the projects to work on in order to become employable in 2025. Here are the results he sent me; my comments are inline on a gray background.

Network Automation with Python

Project: Automate basic network tasks like device configuration, backup, or monitoring using Python scripts.

Dalton Ortega, Cisco Modeling Labs Product Manager, sent me the following email as a response to my Configuring IP Addresses Won't Make You an Expert blog post:

First, your statement on Autonetkit is indeed correct. We had removed that from the product due to lack of popularity. That being said, in our roadmap we are looking at methods to reintroduce on-the-fly configuration as well as enhancing our sample labs library to make getting started with CML easier.

Secondly, CML can be run in full IaC mode because of the API-first build. In fact, many of our customers are using CML as an automated test/validation bed for their CI/CD pipelines. Tools like Ansible and Terraform are available to facilitate this inside CML too. For more details, read:

• Get Started With Terraform and Cisco Modeling Labs
• How to Use Ansible with CML

Another year is almost gone, and it’s time for my traditional “I will disappear until mid-January” retreat (also, don’t expect me to read my email until I’m back).

I hope you’ll also be able to disconnect from the crazy pace of the networking world, forget the “AI will make networking engineers obsolete” shenanigans (hint: SDN did not), and focus on your loved ones. I would also like to wish you all the best in 2025!

I will probably get bored sometime in late December, so expect a few new netlab features in early January.

Addy Osmani published an excellent overview of the challenges of AI-assisted coding. They apply equally well to the “AI will generate device configurations for me” or “AI will troubleshoot my network” ideas (ignoring for the moment the impact of the orders-of-magnitude smaller training set), so it’s definitely worth reading.

I particularly liked the “‌AI is like having a very eager junior developer on your team” take, as well as the description of the “70% problem” (AI will get you 70% there, but the last 30% will be frustrating) – a phenomenon perfectly illustrated by the following diagram by Forrest Brazeal:

When I discovered GitHub Codespaces (thanks to a pointer by Roman Dodin), I did the absolute minimum of research to get netlab up and running in a container to enable Codespaces-based labs (BGP, IS-IS) and netlab examples.

However, if you want to know the behind-the-scenes details, you MUST read the Codespaces for Network Engineers and Educators deep dive by Julio Perez.

One of the key arguments against stretched clusters (and similar stupidities) I used in my Disaster Recovery Myths presentation was the SSD read latency versus cross-site round-trip time.

Thanks to Networking Notes, I found a great infographic I can use in my next presentation (bonus points: it also works great in a terminal when fetched with curl) and a site that checks the latency of your web site from various vantage points.

Would you like to start a tech blog but don’t know how to do it? Ethan Banks put together a phenomenal how-to guide in his Developing Content & Gathering Research For Your Tech Blog article.

Oh, and please use Hugo (or similar) and use walled gardens like LinkedIn solely to post summaries and links to your content. You want to be in control and retain ownership of your work, right?