Not All OSPF Inter-area Traffic Traverses Interfaces In Area 0

Everyone knows that OSPF is a link state protocol. Those that study also discover that OSPF behaves like distance vector between areas as Type-1- and Type-2 LSAs are not flooded between areas, but rather summarized in Type-3 LSAs. This means that OSPF is a logical star, or hub with spokes, where Area 0 is the backbone and all other areas must connect to Area 0. This is shown below:

With this topology, since all the areas only connect to the backbone area, traffic between areas must traverse the backbone:

We learn about this behavior in literature where there is a very straight forward topology where each ABR is only attached to one area beyond the backbone. Such a topology is shown below:

In such a topology, traffic between RT04 and RT05 has to traverse the backbone. This is shown below:

However, what if you have a topology which is not as clear cut? Where an ABR attaches to multiple areas? This is what we will explore in this post. We’ll be using the topology below:

In this topology, RT02 and RT03 are ABRs. RT02 is attached to both Area 1 and Area 2 in addition to the backbone, while RT03 Continue reading

Nvidia Rolls Out Blueprints For The Next Wave Of Generative AI

Hardware is always the star of Nvidia’s GPU Technology Conference, and this year we got previews of “Blackwell” datacenter GPUs, the cornerstone of a 2025 platform that includes “Grace” CPUs, the NVLink Switch 5 chip, the Bluefield-3 DPU, and other components, all of which Nvidia is talking about again this week at the Hot Chips 2024 conference. …

Nvidia Rolls Out Blueprints For The Next Wave Of Generative AI was written by Jeffrey Burt at The Next Platform.

VMware Private Cloud Now Has a Catalog of Advanced Services

Tired of dealing with cloud providers and mulling a move to a private cloud instead? Broadcom wants you to take a look at its operation of a private cloud. This week at Paul Turner, Broadcom vice president of products for VCF, in a press briefing. Broadcom is positioning VCF as a lower-cost, more secure alternative to public cloud computing. Overall, the goal is to help the organization create an infrastructure that works together as a single, unified whole while supporting modern application architectures. Virtual Cloud Foundation architecture (VMware) Big Results Moving to a Private Cloud According to the company, a private cloud approach can result in: Continue reading

Multivendor EVPN Just Works

Shipping netlab release 1.9.0 included running 36 hours of integration tests, including fifteen VXLAN/EVPN tests covering:

  • Bridging multiple VLANs
  • Asymmetric IRB, symmetric IRB, central routing, and running OSPF within an IRB VRF.
  • Layer-3 only VPN, including routing protocols (OSPF and BGP) between PE-router and CE-routers
  • All designs evangelized by the vendors: IBGP+OSPF, EBGP-only (including reusing BGP AS number on leaves), EBGP over the interface (unnumbered) BGP sessions, IBGP-over-EBGP, and EBGP-over-EBGP.

All tests included one or two devices under test and one or more FRR containers1 running EVPN/VXLAN with the devices under test. The results were phenomenal; apart from a few exceptions, everything Just Worked™️.

Read more …

NB492: AMD Spends Big For Engineering Talent; FCC Cracks Down on AI-Faked Robocalls

Take a Network Break! A US appeals court will let a privacy lawsuit against Google go forward, striking telecom workers are a reminder to test your resiliency planning, and AMD spends nearly $5 billion to acquire systems engineering talent from ZT Systems. Juniper Networks offers deep discounts and other enticements to get network engineers to... Read more »

August Rule 11 Academy Update

I’ve been working on new material over at Rule 11 Academy. This month’s posts are:

  • BGP Route Reflector Lab
  • The Clos Fabric (history)
  • The Default Free Zone
  • Network Addresses
  • BGP Policy Entrance Selection (2)
  • Interview Rubric Sample
  • BGP Policy Entrance Select (1)
  • Interviewing Background

    • This brings us up to a total of 39 lessons. Each lesson should be about 15 minutes, so about 10 hours of material so far. The trial membership will take you through the end of the year. After the first of the year, the trial membership will last 2 months.

Network CI/CD Pipeline – What’s the Point?

Network CI/CD Pipeline - What's the Point?

Hi all, welcome to the 'Network CI/CD' blog series. To kick things off, let's ask the question, "Why do we even need a CI/CD pipeline for networks?" Instead of diving straight into technical definitions or showing you how to build a CI/CD pipeline, which might make you lose interest, we’ll focus on the reasons behind it. Why should network teams even consider implementing CI/CD?

In this post, we’ll talk about the benefits and the problems it solves, so you can see why it's worth learning. Let's get to it.

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Throughout this blog post, I’ll use a simple scenario of configuring VLANs. I chose VLANs because it’s something everyone is familiar with, and it’s easy to understand. I could have gone for something more complicated, like BGP or OSPF, but I don’t want to sidetrack our main focus - understanding Network CI/CD pipeline.

Making Network Changes - The Traditional Way

Even though I call it the “traditional way,” most of us (myself included) still make changes via the CLI. So, let’s imagine you and two colleagues are managing a campus network with 10 access switches. One of your tasks is to configure VLANs on all of Continue reading

This AI Network Has No Spine – And That’s A Good Thing

When you are designing applications that run across the scale of an entire datacenter and that are comprised of hundreds to thousands of microservices running on countless individual servers and that have to be called within a matter of microseconds to give the illusion of a monolithic application, building fully connected, high bi-section bandwidth Clos networks is a must. …

This AI Network Has No Spine – And That’s A Good Thing was written by Timothy Prickett Morgan at The Next Platform.

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