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Category Archives for "Networking"

HN784: Accelerate Your Network Automation With Gluware Labs and New Ansible Collection (Sponsored)

Network automation is today’s topic with sponsor Gluware. Gluware provides a network automation platform that targets both network engineers and automation builders. On today’s Heavy Networking, we discuss how Gluware supports these two constituencies. We also talk about a recent product announcement, Gluware Labs. Gluware Labs includes a free Community Edition of Gluware software you... Read more »

Finding End-to-End Paths: Topology and Endpoints

We know there are three main ways to move packets across a network. However, before we can start forwarding packets, someone has to populate the forwarding tables in the intermediate devices or build the sequence of nodes to traverse in source routing.

Usually, whoever is responsible for the contents of the forwarding tables must first discover the network topology. Let’s start there, using the following network diagram to illustrate the discussion.

Juniper vJunos-router in Containerlab

Juniper vJunos-router in Containerlab

If you follow me or read my blog, you probably know I'm a big advocate of Containerlab. I've been using it for over two years now and I absolutely love it. Why? Because it's open source, it has an amazing community behind it (thank you again, Roman), and labs are defined using simple YAML files that are easy to share and reuse.

So far, I've used Cisco IOL, Arista EOS, and Palo Alto VM in Containerlab. And finally, the time came to try Juniper. I decided to test the Juniper vJunos-router, which is a virtualized MX router. It's a single-VM version of vMX that doesn't require any feature licenses and is meant for lab or testing purposes. You can even download the image directly from Juniper's website without needing an account. Thank you, Juniper and Cisco, please take note. In this post, I'll show you how to run Juniper vJunos-router in Containerlab.

Prerequisites

This post assumes you're somewhat familiar with Containerlab and already have it installed. If you're new, feel free to check out my introductory blog below. Containerlab also has great documentation on how to use vJunos-router, so be sure to check that out as well.

N4N029: Four Goals of Network Design

Let’s explore four goals of network design: stability, speed, scalability, and security. These goals are based on Ethan’s experience designing, building, and operating networks. Network architects and design experts might have other objectives, and that’s fine, but these four goals are the basis of today’s episode. Ethan and Holly discuss why these four goals are... Read more »

Weird: Ports on Linux Bridge Are Stuck

Just when you thought you got used to the weirdnesses in the networking implementations, you get a curveball like this one. Life is never dull if you test network devices.

Before releasing netlab release 2.0, I ran the full suite of integration tests for all devices for which I have the images. Interestingly, most VXLAN tests failed for Cumulus Linux 4.x even though we haven’t touched that code for ages.

Next step: trying to figure out what changed. The configuration changes were minimal. Even worse, the failure was non-deterministic. Somehow, we managed to transform a Cumulus Linux 4.x VM into a Heisenberg switch.

D2DO274: Firefly’s State of IaC Report for 2025, aka ClickOps Is a Disgrace (Sponsored)

Firefly is a cloud infrastructure automation platform that helps cloud teams, DevOps, SRE, platform engineering, DevSecOps, and other groups manage their entire cloud as code. Firefly helps to manage cloud complexity and produce consistent and efficient cloud platforms with code. To help Firefly better understand their customers and industry trends around Infrastructure as Code (IaC),... Read more »

Is It Time to Migrate? A Practical Look at Kubernetes Ingress vs. Gateway API

If you’ve managed traffic in Kubernetes, you’ve likely navigated the world of Ingress controllers. For years, Ingress has been the standard way of getting HTTP/S services exposed. But let’s be honest, it often felt like a compromise. We wrestled with controller-specific annotations to unlock critical features, blurred the lines between infrastructure and application concerns, this complexity didn’t just make portability more difficult, it sometimes led to security vulnerabilities and other complications.

As part of Calico Open Source v3.30, we have released a free and open source Calico Ingress Gateway that implements a custom built Envoy proxy with the Kubernetes Gateway API standard to help you navigate Ingress complexities with style. This blog post is designed to get you up to speed on why such a change might be the missing link in your environment.

The Situation: The Ingress Rut

The challenge with traditional Ingress wasn’t a lack of effort, since the landscape is full of innovative solutions. However, the problem was the lack of a unified, expressive, and role-aware standard. Existing ingress controllers were capable, implemented advanced features, however at the same time tied you to a specific project/vendor.

This meant:

What Developers Should Know About Modern CDNs and the Edge

When the web was first scaling up, content delivery networks (CDNs) became a way of dealing with the ever-increasing load. Akamai is widely considered the pioneer of CDN technology in the late-1990s, but arguably it’s been overtaken now by younger, more agile CDN competitors. At least that’s the view of fashions itself as an “edge cloud platform.” “Akamai was the first cloud service, the first multitenant cloud service,” Bergman told The New Stack in an interview. “And I think if they had been developer-friendly, then they should have been as large of a player as AWS, right?” Akamai may not have been the very first cloud service, but it was definitely among the first — and its CDN debuted well before “

Where Are the NETCONF/YANG Tools?

Jo attempted to follow the vendor Kool-Aid recommendations and use NETCONF/YANG to configure network devices. Here’s what he found (slightly edited):


IMHO, the whole NETCONF ecosystem primarily suffers from a tooling problem. Or I haven’t found the right tools yet.

ncclient is (as you mentioned somewhere else) an underdocumented mess. And that undocumented part is not even up to date. The commit hash at the bottom of the docs page is from 2020… I am amazed how so many people got it working well enough to depend on it in their applications.

A Day in the Life of BGP

I want to look at just one day of the operation of the Internet’s BGP network by looking at the behaviour of a single BGP session. Nothing special or extraordinary happened on that day. There were no large-scale power blackouts, no major faults in the world’s submarine cable network, nor in the terrestrial trunk cable systems. No headlining-grabbing cyber attack took place on that day, as far as I’m aware. It was just an ordinary Thursday on the Internet, just like any other day, and I selected this day due to its very ordinariness! WhAt can this day tell us about BGP and the way we use it?

My Experience at AutoCon3

My Experience at AutoCon3

This is my second time attending the AutoCon event. The first one I went to was last year in Amsterdam (AutoCon1), and it was absolutely amazing. I decided to attend again this year, and AutoCon3 took place from the 26th to the 30th of May. The first two days were dedicated to workshops, and the conference itself ran from the 28th to the 30th. I only attended the conference. I heard there were around 650 attendees at this event, which is great to see.

Network Automation Forum (NAF)

In case you’ve never heard of AutoCon, it’s a community-driven conference focused on network automation, organized by the Network Automation Forum (NAF). NAF brings together people from across the industry to share ideas, tools, and best practices around automation, orchestration, and observability in networking.

They typically hold two conferences each year, one in Europe and one in the USA, or at least that’s how it’s been so far. The European event is usually around the end of May, and the US one takes place around November. Tickets are released in tiers, with early bird pricing being cheaper. I grabbed the early bird ticket for 299 euros as soon as it was announced.

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PP065: A Microsegmentation Overview

Microsegmentation divides a network into boundaries or segments to provide fine-grained access control to resources within those segments. On today’s Packet Protector we talk about network and security reasons for employing microsegmentation, different methods (agents, overlays, network controls, and so on), how microsegmentation fits into a zero trust strategy, and the product landscape. Episode Links:... Read more »

Building an AI Agent that puts humans in the loop with Knock and Cloudflare’s Agents SDK

This is a guest post by Chris Bell, CTO of Knock

There’s a lot of talk right now about building AI agents, but not a lot out there about what it takes to make those agents truly useful.

An Agent is an autonomous system designed to make decisions and perform actions to achieve a specific goal or set of goals, without human input.

No matter how good your agent is at making decisions, you will need a person to provide guidance or input on the agent’s path towards its goal. After all, an agent that cannot interact or respond to the outside world and the systems that govern it will be limited in the problems it can solve.

That’s where the “human-in-the-loop” interaction pattern comes in. You're bringing a human into the agent's loop and requiring an input from that human before the agent can continue on its task.

In this blog post, we'll use Knock and the Cloudflare Agents SDK to build an AI Agent for a virtual card issuing workflow that requires human approval when a new card is requested.

You can find the complete code for this example in the repository.

What is Knock?

Knock is messaging Continue reading

Interesting: Bootstrapping HTTPS

Jan Schaumann published an interesting blog post describing the circuitous journey a browser might take to figure out that it can use QUIC with a web server.

Now, if only there were a record in a distributed database telling the browser what the web server supports. Oh, wait… Not surprisingly, browser vendors don’t trust that data and have implemented a happy eyeballs-like protocol to decide between HTTPS over TCP and QUIC.

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