Pytest for Automated Network Testing (I)
Pytest is a Python testing framework. It is primarily used by developers to test their code and make sure it behaves as expected. For example, if you write a function that adds two numbers, you can write a test to verify that the function returns the correct result. If it does, the test passes. If not, the test fails, and pytest tells you exactly where things went wrong.
That is the traditional use case, but pytest is not limited to testing code. You can use it to test anything that can be scripted in Python, and that includes testing your network.
In this series, we will use pytest to write tests that connect to network devices and verify their state. For example, we can write a test that connects to a router and checks whether BGP is up. If BGP is up, the test passes. If not, the test fails. We can also check things like interface states, routing table entries, OSPF neighbours, or really anything else you can pull from a device.
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Pytest is not the only testing framework available in Python. unittest is another popular option and is actually built into the Python standard library, so you Continue reading
D2DO301: Actually Implementing AI
Kyler and Ned are joined by Enrico Teotti, an independent consultant with over 25 years of experience. Enrico has worked with clients on real-world AI implementations, and he’s here talk about what he’s learned, including using AI to query databases, and for debugging and performance analysis. They also touch on the importance of using AI... Read more »VM Migration to Kubernetes: What Breaks and How to Prevent It
Here is what nobody putting together the business case for a VM migration to Kubernetes will tell you upfront: the compute is the easy part.
Moving workloads off vSphere and onto Kubernetes is conceptually straightforward. The tooling has matured. The architecture is proven. Compute moves, storage remaps, and the platform team has a plan.
The network is where projects quietly stall.
Not because the technology does not work. Because nobody scoped the network properly before the project started. A platform migration turned into a multi-team coordination exercise. The firewall team needed a change window. The security team needed to review a network placement that changed when it should not have needed to. The application team discovered hardcoded IPs that nobody documented.
Six months later, half the VMs are still on vSphere and the project is technically “in progress.”
This is not a skills gap. It happens at the most mature organisations with capable teams. It is a scoping problem, and it has a specific cause: the gap between how VM networking works and how Kubernetes networking works is wider than it looks on a migration plan.
This post is for the people who approve these projects. Here is what Continue reading
SONiC Part 1: SONiC Lab Setup on Windows (Step-by-Step)
Introduction
This chapter explains how to build
a SONiC virtual test environment on a Windows computer. First, we enable the
required Windows features for WSL 2 and update and verify the WSL installation.
Next, we install an Ubuntu distribution and validate that the Linux environment
is working correctly, including basic resource checks (CPU, memory, and disk).
After the Linux environment is ready, we install Docker Engine from Docker’s
official repository and complete the required post-installation steps to run
containers. We then install Containerlab, download the SONiC virtual switch
image (docker-sonic-vs.gz), copy it into WSL, and load it into Docker.
Finally, we install Visual Studio Code on Windows and connect it to WSL to make
creating and editing the YAML topology files easier. The next chapter uses this
environment to define and deploy a simple SONiC-based topology.
Phase 1: Enable Features for WSL
WSL 2 requires two Windows
features to be enabled. The first feature, Microsoft-Windows-Subsystem-Linux
(Example 1-1), enables WSL. The second feature, VirtualMachinePlatform
(Example 1-2), is required to run WSL 2.
In this
example, both features are enabled using Microsoft PowerShell (Run as
Administrator) with the dism.exe command. The options used are:
On Generating EVPN MAC/IP Routes
Naveen Kumar Devaraj was reading my Integrated Routing and Bridging (IRB) with EVPN MAC-VRF Instances lab exercise and spotted this detail:
Arista EOS originates MAC-IP routes with and without IP addresses, effectively doubling the size of the EVPN BGP table
He kindly wrote a LinkedIn comment explaining that behavior:
HW076: Linux for the WLAN Professional
What separates good Wi-Fi engineers from ones who really can troubleshoot anything? Linux. Understanding Linux—from packet capture workflows to using tcpdump to how USB NIC drivers work—will set you apart from other engineers. Guest Bryan Ward joins the show to break down why you need to know Linux as a WLAN professional and how you... Read more »PP107: Why Now’s the Time to Prepare for a Post-Quantum World (Sponsored)
A cryptographically relevant quantum computer is, at some point, going to emerge that can crack modern encryption. But we don’t know when, so it’s tempting to set this problem aside. On today’s sponsored episode, we talk about why ignoring Post-Quantum Cryptography (PQC) isn’t an effective strategy. Sponsor Cisco is here to make the case for... Read more »Shutdowns, power outages, and conflict: a review of Q1 2026 Internet disruptions
In the first quarter of 2026, government-directed shutdowns figured prominently, with prolonged Internet blackouts in both Uganda and Iran, a stark contrast to the lack of observed government-directed shutdowns in the same quarter a year prior. This quarter, we also observed a number of Internet disruptions caused by power outages, including three separate collapses of Cuba's national electrical grid. Military action continued to disrupt connectivity in Ukraine and also impacted hyperscaler cloud infrastructure in the Middle East. Severe weather knocked out Internet connectivity in Portugal, while cable damage disrupted connectivity in the Republic of Congo. A technical problem hit Verizon Wireless in the United States, and unknown issues briefly disrupted connectivity for customers of providers in Guinea and the United Kingdom.
This post is intended as a summary overview of observed and confirmed disruptions and is not an exhaustive or complete list of issues that have occurred during the quarter. A larger list of detected traffic anomalies is available in the Cloudflare Radar Outage Center. Note that both bytes-based and request-based traffic graphs are used within this post to illustrate the impact of the observed disruptions, with the choice of metric generally made based on which better illustrates the Continue reading
Worth Reading: Lab as Code (containerlab and netlab)
@sjhloco wrote an excellent in-depth description of how you can use containerlab and netlab to manage your labs as code.
He also documented a few netlab shortcomings (one of which caused a crash); fortunately, I found his blog post (admittedly over a year later) and fixed most of them in release 26.04:
NB572: Quantum Switches and Flying Cars
Take a Network Break! We start with follow up on Anthropic’s Project Glasswing and Linux 7.0. On the news side, Cisco announces a prototype quantum switch that promises to support multiple quantum encoding modalities, Cato Networks adds an enterprise browser to its security offerings, and Mozilla validates the bug-finding powers of Anthropic’s Mythos model. Anthropic... Read more »You Can’t Patch People
One of the things I’ve noticed when it comes to IT is how quickly we’re willing to use software to solve people problems. Over my career I’ve seen all manner of crazy solutions to get around people being lazy or uneducated. Remember vMotion? Or OTV for stretched layer 2? Why do you think those solutions came about? I posit that it’s because it’s faster to write software than to patch people.
Hacking Humans
I see this most often in cybersecurity. Developers love to create software solutions that prevent things from happening. Phishing and all its various forms are some of the top priorities for solutions that prevent leaking of information. While we have invested a lot in phishing tests and education it’s also very likely that there are controls in place that prevent users from accidentally giving out information to threat actors.
Why are we so willing to write software to fix problems instead of teaching people to avoid those issues? I think in part it’s because software is predictable. If I create an app or write some controls into a platform it’s going to behave the same way every time. That’s the definition of deterministic. Every time the software Continue reading
Revocation
How have we got to the point where certificates cannot be revoked?TNO061: Networking Theory and Practice; Networking in the Classroom Today
Scott Robohn sits down with Andy Smith, a distinguished engineer with Arrcus Networks, where he and his team work to advance networking with modern software and new architectures. He’s also a lecturer at the School of Engineering and Applied Science at the University of Pennsylvania. Andy shares his networking journey, talks about how networks and... Read more »HN824: That’s Not a Job for an LLM: The Right Way to Apply AI to Network Operations (Sponsored)
On today’s sponsored Heavy Networking, we get off the AI hype train to talk about how different artificial intelligence techniques usefully impact network operations—and where they aren’t a fit. The various forms of AI represent a set of tools that, like any tool, have use cases, capabilities, and limitations. Our guest is Avi Freedman, CEO... Read more »State of Network Automation with Urs Baumann
I stopped tracking the (lack of) progress in network automation years ago, when I realized I had nothing new to say. As an eternal optimist, I hoped I was just missing something, but Urs Baumann (the guest of Software Gone Wild Episode 206) destroyed my hopes when he said, “I can still use the same slides I created 10 years ago”. On a more positive note, he recently completed his Master’s thesis on AI in network engineering, so we ended with a nice chat on its potential impact.
Hedge 303: Data Centers?
In this roundtable episode of the Hedge, Eyvonne, Tom, and Russ hang out and talk about data centers–why are we building all these things again? Our second topic is the FCC’s ban on non-US made home routers. Was this the right thing to do? Was it the wrong thing to do? Were there any other policy options?
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LIU013: The Engineer Who Built a Business to Fund a Mission
Ray Cline has been in the tech trenches since he was twelve years old, helping his Dad run a bulletin board service. Today he runs an MSP called Libertas Consulting and leads a nonprofit called TEKnowledge Worldwide (TKW) that has donated over a million dollars in network infrastructure to communities in need. Join us for... Read more »Keindahan Danau Moat di Bolaang Mongondow Timur, Sulawesi Utara
Mengenal Danau Moat
Danau Moat adalah salah satu destinasi alam menakjubkan yang terletak di Moat, Modayag, Kabupaten Bolaang Mongondow Timur, Sulawesi Utara. Danau ini menawarkan pemandangan alami yang memesona dan menjadi sumber kehidupan bagi masyarakat sekitar. Setiap pengunjung yang datang akan langsung merasakan ketenangan dan kesegaran udara yang jarang ditemukan di daerah perkotaan.
Selain keindahan alamnya, Danau Moat juga memiliki keanekaragaman hayati yang menarik. Airnya yang jernih menampung berbagai spesies ikan lokal, sementara tepiannya dipenuhi oleh pepohonan hijau yang menambah suasana damai. Dengan lokasi yang mudah dijangkau, danau ini menjadi tempat favorit untuk wisata keluarga, fotografi alam, dan rekreasi edukatif.
Aktivitas Wisata di Danau Moat
Pengunjung bisa melakukan berbagai aktivitas di sekitar Danau Moat. Pertama, memancing adalah kegiatan yang populer karena danau ini kaya dengan ikan air tawar. Selain itu, banyak pengunjung memilih berperahu untuk menikmati keindahan danau dari perspektif berbeda.
Selanjutnya, berkemah di tepi danau menjadi pengalaman yang tak terlupakan. Dengan suasana yang sejuk dan tenang, pengunjung bisa merasakan kedekatan dengan alam sambil menikmati matahari terbenam. Untuk para pecinta fotografi, Danau Moat menawarkan view eksotis yang sempurna untuk menangkap pemandangan alam Sulawesi Utara.
Flora dan Fauna di Sekitar Danau
Flora di sekitar danau sangat Continue reading
Tembok Besar Gorgan: Benteng Kuno Terpanjang Iran
Sejarah dan Keunikan Tembok Besar Gorgan
Tembok Besar Gorgan merupakan struktur pertahanan kuno yang membentang di timur laut Iran. Dibangun sekitar abad ke-5 Masehi, tembok ini menjadi simbol kekuatan militer dinasti Sassanid. Menakjubkannya, panjang tembok ini hampir setara dengan 200 km, menjadikannya terpanjang kedua setelah Tembok Besar Tiongkok.
Tembok Gorgan dirancang untuk melindungi wilayah dari serangan nomaden dari utara. Selain itu, benteng ini menunjukkan kemampuan teknik sipil yang tinggi, dengan bahan bangunan yang tahan lama, termasuk bata merah dan batu alam lokal. Dengan parit besar dan menara pengawas setiap beberapa ratus meter, pertahanan ini memberikan kontrol strategis atas rute perdagangan dan migrasi.
Struktur dan Arsitektur Tembok
Tembok Besar Gorgan memiliki arsitektur yang kompleks. Panjangnya membentang dari Laut Kaspia hingga Pegunungan Pishkamar, melintasi lembah dan dataran tinggi. Benteng ini memiliki parit lebar di satu sisi dan dinding batu setinggi lebih dari 6 meter di sisi lain.
| Fitur Utama | Detail |
|---|---|
| Panjang | ±200 km |
| Tinggi dinding | 6–8 meter |
| Lebar dinding | 3 meter |
| Menara pengawas | Setiap 10–15 km |
| Bahan | Bata merah, batu lokal |
Selain itu, menara pengawas dan pos militer kecil tersebar sepanjang tembok, memungkinkan pengawasan efektif terhadap gerakan musuh. Arsitektur ini menunjukkan strategi pertahanan berlapis, yang jarang ditemukan pada benteng Continue reading