Author Archives: Ivan Pepelnjak
Author Archives: Ivan Pepelnjak
One of my readers sent me this question (probably after stumbling upon a remark I made in the AWS Networking webinar):
You had mentioned that AWS is probably not using EVPN for their overlay control-plane because it doesn’t work for their scale. Can you elaborate please? I’m going through an EVPN PoC and curious to learn more.
It’s safe to assume AWS uses some sort of overlay virtual networking (like every other sane large-scale cloud provider). We don’t know any details; AWS never felt the need to use conferences as recruitment drives, and what little they told us at re:Invent described the system mostly from the customer perspective.
One of my readers sent me this question (probably after stumbling upon a remark I made in the AWS Networking webinar):
You had mentioned that AWS is probably not using EVPN for their overlay control-plane because it doesn’t work for their scale. Can you elaborate please? I’m going through an EVPN PoC and curious to learn more.
It’s safe to assume AWS uses some sort of overlay virtual networking (like every other sane large-scale cloud provider). We don’t know any details; AWS never felt the need to use conferences as recruitment drives, and what little they told us at re:Invent described the system mostly from the customer perspective.
In mid-September, Carl Buchmann, Fred Hsu, and Thomas Grimonet had an excellent presentation describing Arista’s Ansible roles and collections. They focused on two collections: CloudVision integration, and Arista Validated Designs. All the videos from that presentation are available with free ipSpace.net subscription.
Want to know even more about Ansible and network automation? Join our 2-day automation event featuring network automation experts from around the globe talking about their production-grade automation solutions or tools they created, and get immediate access to automation course materials and reviewed hands-on exercises.
In mid-September, Carl Buchmann, Fred Hsu, and Thomas Grimonet had an excellent presentation describing Arista’s Ansible roles and collections. They focused on two collections: CloudVision integration, and Arista Validated Designs. All the videos from that presentation are available with free ipSpace.net subscription.
Want to know even more about Ansible and network automation? Join our 2-day automation event featuring network automation experts from around the globe talking about their production-grade automation solutions or tools they created, and get immediate access to automation course materials and reviewed hands-on exercises.
While I keep telling you that Google-sized solutions aren’t necessarily the best fit for your environment, some of the hyperscaler presentations contain nuggets that apply to any environment no matter how small it is.
One of those must-watch presentations is Fault Tolerance through Optimal Workload Placement together with a wonderful TL&DR summary by the one-and-only Todd Hoff of the High Scalability fame.
While I keep telling you that Google-sized solutions aren’t necessarily the best fit for your environment, some of the hyperscaler presentations contain nuggets that apply to any environment no matter how small it is.
One of those must-watch presentations is Fault Tolerance through Optimal Workload Placement together with a wonderful TL&DR summary by the one-and-only Todd Hoff of the High Scalability fame.
Justin Pietsch is back with another must-read article, this time focused on high-speed Ethernet switching ASICs. I’ve rarely seen so many adjacent topics covered in a single easy-to-read article.
Justin Pietsch is back with another must-read article, this time focused on high-speed Ethernet switching ASICs. I’ve rarely seen so many adjacent topics covered in a single easy-to-read article.
James Miles got tons of really interesting questions while watching the Network Operating System Models webinar by Dinesh Dutt, and the only reasonable thing to do when he sent them over was to schedule a Q&A session with Dinesh to discuss them.
We got together last week and planned to spend an hour or two discussing the questions, but (not exactly unexpectedly) we got only halfway through the list in the time we had, so we’re continuing next week.
James Miles got tons of really interesting questions while watching the Network Operating System Models webinar by Dinesh Dutt, and the only reasonable thing to do when he sent them over was to schedule a Q&A session with Dinesh to discuss them.
We got together last week and planned to spend an hour or two discussing the questions, but (not exactly unexpectedly) we got only halfway through the list in the time we had, so we’re continuing next week.
Contrary to what some evangelists would love you to believe, getting fluent in network automation is a bit harder than watching 3-minute videos and cobbling playbooks together with google-and-paste… but then nothing really worth doing is ever easy, or everyone else would be doing it already.
Here’s a typical comment from a Building Network Automation Solutions attendee:
I’m loving the class. I feel more confused than I ever have in my 23 year career… but I can already see the difference in my perspective shift in all aspects of my work.
Contrary to what some evangelists would love you to believe, getting fluent in network automation is a bit harder than watching 3-minute videos and cobbling playbooks together with google-and-paste… but then nothing really worth doing is ever easy, or everyone else would be doing it already.
Here’s a typical comment from a Building Network Automation Solutions attendee:
I’m loving the class. I feel more confused than I ever have in my 23 year career… but I can already see the difference in my perspective shift in all aspects of my work.
Post-quantum cryptography (algorithms resistant to quantum computer attacks) is quickly turning into another steaming pile of hype vigorously explored by various security vendors.
Christoph Jaggi made it his task to debunk at least some of the worst hype, collected information from people implementing real-life solutions in this domain, and wrote an excellent overview article explaining the potential threats, solutions, and current state-of-the art.
You (RFC 6919) OUGHT TO read his article before facing the first vendor presentation on the topic.
Post-quantum cryptography (algorithms resistant to quantum computer attacks) is quickly turning into another steaming pile of hype vigorously explored by various security vendors.
Christoph Jaggi made it his task to debunk at least some of the worst hype, collected information from people implementing real-life solutions in this domain, and wrote an excellent overview article explaining the potential threats, solutions, and current state-of-the art.
You (RFC 6919) OUGHT TO read his article before facing the first vendor presentation on the topic.
The mission of ipSpace.net is very simple: explain new networking technologies and products in a no-nonsense marketing-free and hopefully understandable way.
Sometimes we’re probably way off the mark, but every now and then we get it just right as evidenced by this feedback from one of our subscribers:
I was given short notice to present a board-level overview of VMWare NSX-T for an urgent virtualization platform change from Microsoft. Tech execs needed to understand NSX-T’s position in the market, in its product lifecycle, feature advantages, possible feature deficits, and an idea of the level of effort for implementation.
The mission of ipSpace.net is very simple: explain new networking technologies and products in a no-nonsense marketing-free and hopefully understandable way.
Sometimes we’re probably way off the mark, but every now and then we get it just right as evidenced by this feedback from one of our subscribers:
I was given short notice to present a board-level overview of VMWare NSX-T for an urgent virtualization platform change from Microsoft. Tech execs needed to understand NSX-T’s position in the market, in its product lifecycle, feature advantages, possible feature deficits, and an idea of the level of effort for implementation.
Got this interesting question from one of my readers
Based on my experience, the documentation regarding Linux networking is either elementary man pages for user-space utilities or very complicated Linux kernel source code. Does getting deep into Linux networking mean reading source code?
It all depends on how deep you plan to go:
Deploying whitebox switches. If you’re just starting you SHOULD buy a supported solution that includes hardware and a variant of Linux running on it. Your problem transformed into “configuring control-plane protocols on Linux”. Congratulations, you’ll be perfectly fine studying Cumulus Networks documentation. Apart from the secret-sauce-ASIC-blob they’re using open-source software, so whatever you learn there should be transferrable to any other Linux networking environment.
However, even though the documentation is pretty good, expect a few gotchas. As Dinesh Dutt told me:
Russ White published an interesting story explaining why we’re using IP and not CLNS to build today’s Internet.
Let’s start with a few minor details he missed that I feel obliged to point out (apologies to Russ for being too pedantic, but you know me…):
In one of his recent blog posts Tom Hollingsworth described what I semi-consciously felt about the CCIE lab exam for at least 25 years: it’s full of contrived scenarios that look more like Iron Chef than real life.
I understand they had to make the lab harder and harder to stop cheating (because talking with candidates and flunking the incompetents is obviously not an option), and there’s only so much one can do with a limited set of technologies… but forcing networking engineers to find ever-more-devious ways to solve overly-complex problems is nothing else but fuel for rampant MacGyverism.
Anyway, I don’t think this mess will ever be fixed, so the only thing we can do is to enjoy the rant.
If you’re working solely with IP-based networks, you’re probably quick to assume that hop-by-hop destination-only forwarding is the only packet forwarding paradigm that makes sense. Not true, even today’s networks use a variety of forwarding mechanisms, most of them called some variant of routing or switching.
What exactly is the difference between the two, and what is bridging? I’m answering these questions (and a few others like what’s the difference between data-, control- and management planes) in the Bridging, Routing and Switching Terminology video.