1000BASE-T Part 1 – Introduction

How does Ethernet detect that a link goes down? This, what I thought was a simple question, I asked myself a couple of weeks ago. I realized I didn’t have a very good answer. I realized I had more to learn about Ethernet and the physical layer and so does pretty much the entire networking industry. Through the graceful help of Peter Jones at Cisco, I got in touch with George Zimmerman, an independent professional with a PhD in electrical engineering, a history of teaching at Caltech, and that works within the IEEE on different standards. To answer my initial question, we first need to understand more about Ethernet, and especially the physical layer. As every version of Ethernet has slightly different PHY, I will be covering 1000BASE-T. This will be covered in a series of posts, this being the first.

Going back to the OSI model, most roles in networking puts the focus on layers two to four:

This is natural as most of our work relates to these layers.

When we think of two hosts communicating, we imagine that the transceivers connect to each other and that there are ones and zeroes traveling across the cable:

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FRRouting Claims IBGP Loopbacks Are Inaccessible

Last week, I explained the differences between FRRouting and more traditional networking operating systems in scenarios where OSPF and IBGP advertise the same prefix:

  • Traditional networking operating systems enter only the OSPF route into the IP routing table.
  • FRRouting enters OSPF and IBGP routes into the IP routing table.
  • On all platforms I’ve tested, only the OSPF route gets into the forwarding table1.

One could conclude that it’s perfectly safe to advertise the same prefixes in OSPF and IBGP. The OSPF routes will be used within the autonomous system, and the IBGP routes will be propagated over EBGP to adjacent networks. Well, one would be surprised 🤦‍♂️

Getting Started With Juniper PyEZ Library

Getting Started With Juniper PyEZ Library

In this blog post, we're diving into how to use the PyEZ Python library to interact with Juniper devices. I'll be working with a Juniper vMX device as our example, but PyEZ can work with any other Junos-based device. So, whether you have a vMX, an SRX, or any other Junos device, you'll find this guide helpful.

What we will cover?

  • What is Juniper PyEZ?
  • Why do we need PyEZ?
  • Prerequisites
  • Getting facts from Juniper vMX
  • Getting Interface Stats and Errors
  • A few things to note
  • Closing thoughts

What is Juniper PyEZ?

Junos PyEZ is a microframework for Python that enables you to manage and automate Junos devices. Junos PyEZ is designed to provide the capabilities that we would typically get from the CLI.

You can use Junos PyEZ to retrieve facts or operational information from a device, execute remote procedure calls (RPC) available through the Junos XML API and even install or upgrade the Junos software. But for the sake of this example, we will retrieve the facts from the vMX and then retrieve some interface statistics.

But, Why Do I need PyEZ?

If you're wondering why we need PyEZ, here's a straightforward reason from my experience. I often Continue reading

Recap: KubeCon + CloudNativeCon EU + CalicoCon 2024

Last week we had the pleasure of attending KubeCon + CloudNativeCon EU in Paris, France. It was a fantastic event where we once again had the opportunity to engage in meaningful conversations about Kubernetes, container security, and the latest developments in the open source ecosystem. We also hosted CalicoCon 2024, a co-located event, to talk about our favorite subject: Calico! Let’s take a look at some of the highlights from the conference.

CalicoCon 2024

A large group of KubeCon attendees joined us on March 19th for a full-day event to explore the trends, strategies, and technologies making waves in the Kubernetes networking, security, and observability world. The day included a keynote on Project Calico’s past, present, and future, plus multiple presentations and workshops delivered by Calico engineers that provided a deep dive into topics such as eBPF, Windows HNS, multi-cluster mesh, best practices for network policies, scale, performance, encryption, and compliance.

A good time was had by all in attendance, and two lucky winners of our raffles each took home a pair of AirPods! The day ended with happy hour and networking, where attendees had a chance to meet other Calico users as well as the engineers and leadership Continue reading

Cisco Live 2024 – an Englishman in Vegas

Once again this year, Cisco Live US 2024 will take place in Las Vegas, Nevada, from June 2 to 6, 2024. I’m already registered and I’m looking forward to it! This year will be my 11th time attending Cisco’s annual conference in person, in both Europe and the United States.   Straight to the point I’ve already written a few posts in previous years about what’s interesting to see and do at Cisco Live, and whether the conference is worth attending in person (and of course, it’s worth it!). This…

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The New AI Era: Networking for AI and AI for Networking*

As we all recover from NVIDIA’s exhilarating GTC 2024 in San Jose last week, AI state-of-the-art news seems fast and furious. Nvidia’s latest Blackwell GPU announcement and Meta’s blog validating Ethernet for their pair of clusters with 24,000 GPUs to train on their Llama 3 large language model (LLM) made the headlines. Networking has come a long way, accelerating pervasive compute, storage, and AI workloads for the next era of AI. Our large customers across every market segment, as well as the cloud and AI titans, recognize the rapid improvements in productivity and unprecedented insights and knowledge that AI enables. At the heart of many of these AI clusters is the flagship Arista 7800R AI spine.

NB471: Nvidia Unveils 800G Ethernet, InfiniBand Switches For AI Fabrics; ‘Ghost Jobs’ Haunt Job Boards

Take a Network Break! Nvidia announces new 800G switches, one for Ethernet and one for InfiniBand, for building AI fabrics. Nvidia also announces an “AI supercomputer,” a rack-scale pre-built bundle of Nvidia GPUs and CPUs connected via InfiniBand switches. The NaaS startup Meter announces new campus switches and what it calls a “digital twin” capability,... Read more »