Archive

Category Archives for "Networking"

The Inattention Economy

I need you to try to do something very hard for me. I need you to read this entire blog post. I don’t think it’s going to be hard because I’m going to use big words or highly technical terms. I don’t think it’s going to be hard because of the subject matter. It’s going to be hard because you’re going to get interrupted. In fact, I’m willing to be you got some notification before you ever finished this paragraph.

I didn’t realize just how scattered my attention was until a close friend pointed it out to me. She mentioned that I was always checking my watch for notifications. I didn’t realize it until someone that wasn’t around me all the time saw it. I stepped back and honestly asked myself why I was getting so many notifications. In the back of my mind I knew I was getting too many because when I go on a run my watch won’t stop buzzing with all the things that I don’t even bother to check. That’s when I realized my attention was beyond Continue reading

Introducing Markdown for Agents

The way content and businesses are discovered online is changing rapidly. In the past, traffic originated from traditional search engines, and SEO determined who got found first. Now the traffic is increasingly coming from AI crawlers and agents that demand structured data within the often-unstructured Web that was built for humans.

As a business, to continue to stay ahead, now is the time to consider not just human visitors, or traditional wisdom for SEO-optimization, but start to treat agents as first-class citizens. 

Why markdown is important

Feeding raw HTML to an AI is like paying by the word to read packaging instead of the letter inside. A simple ## About Us on a page in markdown costs roughly 3 tokens; its HTML equivalent – <h2 class="section-title" id="about">About Us</h2> – burns 12-15, and that's before you account for the <div> wrappers, nav bars, and script tags that pad every real web page and have zero semantic value.

This blog post you’re reading takes 16,180 tokens in HTML and 3,150 tokens when converted to markdown. That’s a 80% reduction in token usage.

Markdown has quickly become the lingua franca for agents and AI systems as a whole. The format’s explicit structure Continue reading

Kubernetes Network Observability: Comparing Calico, Cilium, Retina, and Netobserv

Calico, Cilium, Retina, and Netobserv: Which Observability Tool is Right for Your Kubernetes Cluster? Network observability is a tale as old as the OSI model itself and anyone who has managed a network or even a Kubernetes cluster knows the feeling: a service suddenly can’t reach its dependency, a pod is mysteriously offline, and the Slack alerts start rolling in. Investigating network connectivity issues in these complex, distributed environments can be incredibly time consuming. Without the right tools, the debugging process often involves manually connecting to each node, running tcpdump on multiple machines, and piecing together logs to find the root cause. A path that often leads to frustration and extended downtime.

This is the problem that Kubernetes Network Observability was built to solve. By deploying distributed observers, these cloud-native solutions take the traditional flow entries and enrich them with Kubernetes flags and labels to allow Kubernetes users to get insight into the inner workings of their clusters.

This blog post aims to give you a rundown of the leading solutions in the CNCF ecosystem, and compare how they track a packet’s journey across your cluster.

Feature Comparison Matrix

Before diving into the specifics, let’s look at how these four Continue reading

NAN113: What Works, and What Doesn’t, in Network Automation Projects

Today we are joined by Matt Remke, who has spent years in the trenches of network automation projects as a consultant. Matt offers a unique, non-engineer perspective on scaling network automation in real-world, complex environments for some of the world’s largest companies. Matt shares what worked, what backfired, and the hard-earned lessons he has gained... Read more »

netlab 26.02: KinD support, more EVPN/VXLAN

netlab release 26.02 is out, including the usual potpourri of goodies:

  • Support for Kubernetes (KinD) clusters based on work by @wnagele
  • Layer-2 EVPN/VXLAN support on Cat8000v, IOL, and IOLL2
  • netlab graph command can create graphs from a subset of nodes or links
  • You can specify the parameters of core links in the fabric plugin
  • OSPFv3 reports

The fun part, however, are the new container configuration methods:

PP096: Taking Note of a Notepad++ Attack; Telnet and NTLM Are Still a Thing?

Everything old is new again in today’s Packet Protector news roundup, as a decade-old Telnet exploit resurfaces, and Microsoft unfolds its roadmap to phase out the ancient NTLM protocol. In other news, Google takes down a sprawling residential proxy network, the popular Notepad++ app takes steps to recover from a serious compromise, and a Polish... Read more »

Multicast PIM Auto RP (V)

Multicast PIM Auto RP (V)

In the previous posts in this series, we covered the basics of multicast, IGMP, PIM Dense Mode, and PIM Sparse Mode. In the Sparse Mode post, we manually configured the RP address on every router in the network. This works fine in a small lab, but in a larger network with many routers, it becomes difficult to manage. If the RP changes, you have to update the configuration on every single router.

Multicast PIM Sparse Mode
Sparse Mode only sends traffic to parts of the network that explicitly request it. Routers with interested receivers send Join messages toward
Multicast PIM Auto RP (V)

AutoRP solves this problem by allowing routers to dynamically learn the RP address. Instead of manually configuring the RP on each router, you configure one or more routers to announce themselves as Candidate RPs. A separate router (or the same as the Candidate RP router) called the Mapping Agent collects these announcements and distributes the RP information to all other routers in the network. This makes RP management much easier and also provides a way to implement RP redundancy.

There are two methods to dynamically learn the RP address, which are Auto-RP and Bootstrap Router (BSR). In this Continue reading

Open-Source Network Simulators (2026 Edition)

Brian Linkletter published an updated overview of open-source network simulators and emulators.

containerlab and GNS3 are clear leaders (no surprise there) with the original vrnetlab becoming abandonware (fortunately, we have Roman Dodin’s fork), which makes me think we should focus on using netlab primarily with containerlab and slowly sunset the Vagrant support, particularly considering some people actively hate the license change.

Also, if anyone feels like writing an interface (provider module) between netlab and GNS3, the pull request would be most welcome 😎

Any thoughts? Please leave a comment!

NB561: Kubernetes Retires Ingress NGINX; Are Data Centers Headed for Orbit?

Take a Network Break! We start with a trio of follow-ups, including a correction regarding Mplify certifications, Cisco proposing new OSI layers, and free-space optics. Our Red Alert sounds off about a remote code execution vulnerability in the Ivanti Endpoint Manager Mobile agent. On the news front, Broadcom announces new silicon for wireless APs for... Read more »

Fast Arista cEOS Container Configuration

After the enormous speedup I achieved with the FRR containers, I tried to do something similar with the Arista cEOS ones. After all, Arista’s pretty open about running its software on standard Linux, so it should be possible to map host-side configuration files into container-side scripts and execute them, right?

There was just one tiny gotcha: all netlab-generated EOS configuration files are device configuration snippets that are intended to be submitted via EOS CLI, and I didn’t feel like cracking open the netmiko documentation (that’s another backburner project).

However, Arista cEOS includes this magic command called FastCli ;)

Fragments of an adolescent web

I have unearthed a few old articles typed during my adolescence, between 1996 and 1998. Unremarkable at the time, these pages now compose, three decades later, the chronicle of a vanished era.1

The word “blog” does not exist yet. Wikipedia remains to come. Google has not been born. AltaVista reigns over searches, while already struggling to embrace the nascent immensity of the web2. To meet someone, you had to agree in advance and prepare your route on paper maps. 🗺️

The web is taking off. The CSS specification has just emerged, HTML tables still serve for page layout. Cookies and advertising banners are making their appearance. Pages are adorned with music and videos, forcing browsers to arm themselves with plugins. Netscape Navigator sits on 86% of the territory, but Windows 95 now bundles Internet Explorer to quickly catch up. Facing this offensive, Netscape opensource its browser.

France falls behind. Outside universities, Internet access remains expensive and laborious. Minitel still reigns, offering phone directory, train tickets, remote shopping. This was not yet possible with the Internet: buying a CD online was a pipe dream. Encryption suffers from inappropriate regulation: the DES algorithm is capped at 40 bits and Continue reading

Multicast PIM Sparse Mode (IV)

Multicast PIM Sparse Mode (IV)

In the previous post, we covered PIM Dense Mode and mentioned that it is not widely used in production because of its flood and prune behaviour. Every router in the network receives the multicast traffic first, and then routers without interested receivers have to send prune messages. This is inefficient, especially in large networks.

Multicast PIM Dense Mode
PIM Dense mode assumes that every subnet in the network has interested receivers, so it floods multicast traffic everywhere first. Routers that
Multicast PIM Sparse Mode (IV)

In this post, we will look at PIM Sparse Mode, which takes the opposite approach. Instead of flooding traffic everywhere and pruning where it is not needed, Sparse Mode only sends traffic to parts of the network that explicitly request it. Routers with interested receivers send Join messages and only then does the multicast traffic start flowing. This makes Sparse Mode much more efficient and scalable, which is why it is the preferred mode in most production networks today.

PIM Spare Mode Overview

In Dense Mode, we saw two main problems. Multicast traffic is flooded everywhere, and every router has to maintain state for every multicast group, even if all its interfaces are pruned. Sparse Mode Continue reading

HN813: What Should Networkers Know About Software Development (and Vice Versa)?

What should network engineers know about software development? What should software developers know about networking? Ethan and Drew sit down with Chris Rapier and Nick Buraglio to discuss why crossing these silos can improve outcomes for everyone. They break down why being a little curious about the infrastructure can help software developers write better code,... Read more »