Human Infrastructure 348: Happy Anniversary Cat6K!

April 04, 2024

THIS WEEK’S MUST-READ BLOGS 🤓

Cisco Cat6K 25th Anniversary 
There’s no link here, but I caught on LinkedIn that the venerable Cisco Catalyst 6K product is celebrating its 25th anniversary. I found this from Cisco’s blog celebrating the 20th anniversary, and the math adds up. When the apocalypse comes, I believe a Cat6509 will be the last switch running before the world returns to the stone age. If you’ve still got a 65xx in production, I would love to hear about it via the Packet Pushers follow-up page. What model? What’s it used for? Does it have a pet name? Do you feel affection for it? - Ethan

This story from 2022 takes the operating system view of what it means to “listen on a port”. Do you know what it means? Can you explain it? This article goes through several iterations of simple Python to illustrate what’s actually happening when binding a socket to a port. - Ethan

Mehdi Sfar takes on the design challenge of how to handle a BFD session that’s running across a LAG. This is a complex scenario because BFD timers are intentionally aggressive, probably more so than a LAG bundle’s. Thus, if the BFD session is hashed over a LAG member link that fails, BFD will decide the session has failed before the LAG has a chance to hash the BFD session over a different link. Mehdi also points out that BFD headed in one direction might be hashed to one LAG member, while the BFD traffic headed the other direction might get hashed to a different one! What’s the best way to deal with BFD over LAG then? Mehdi suggests various options including getting rid of the BFD session if you don’t need it, replacing the LAG with an appropriately sized single link, and more. The one that especially caught my eye was called Micro-BFD, based on the IETF’s RFC 7130. If your NOS supports RFC 7130, the BFD session becomes LAG-aware, running BFD sessions across each LAG member link. Today I learned! - Ethan

Bryan Sullins wins the Internet today. That is all. - Ethan

1000BASE-T Part 2 - Lost In Transit

How does Ethernet detect that a link has gone down? That seemingly simple question sent Daniel Dib on a deep-dive into the physical layer. He shares his learning in a two-part series. - Drew

TECH NEWS 📣

Broadcom’s changes to VMware pricing have upset many, with reports of massive price increases making their way to the Packet Pushers. But Broadcom is arguing that complaints about higher prices are unwarranted since customers using at least two components of VMware's flagship Cloud Foundation will end up paying less and because the new pricing includes support, which VMware didn't include before. VCF is also going to be updated in July so that a single license key unlocks the entire product. Then in 1H2025, VCF 9 will be released and users with multiple VMware products would no longer need individual silos for discrete storage. We’ll be talking to Broadcom/VMware about all the changes in the coming weeks. If you have questions you want us to relay, send them along to us via our follow-up page. We’ll do what we can. - Ethan

The United States Federal Communications Commission (FCC) will restore the standard of net neutrality, where internet service providers should enable access to all content and applications regardless of the source, and without favoring or blocking particular products or websites. Without net neutrality, ISPs could more easily engage in anti-competitive practices, reducing the usefulness of the Internet as a communications network for the common good. - Ethan

While it’s possible to push a lot more data through fiber, those other techniques require new fiber. The advantage of this breakthrough is that you can push 301,000 Gbps through existing fiber, i.e. no new fiber required. From the piece…“In contrast, MBT (multiband transmission), while limited in overall bandwidth to that of the installed standard single mode fibre (SSMF), requires system upgrade only at the node and operator level,” researchers wrote. They add that their experiment was carried out over a 50 kilometer-long optical fiber. Specifically, the team developed “optical amplifiers and optical gain equalizers,” which can tap the E-band and S-bans, alongside the already commercialized C and L-bands. “Before the development of our device, no one had been able to properly emulate the E-band channels in a controlled way,” [Dr. Ian] Phillips said. - Ethan

The click-baity headline is referring to the issues many of us working with LLMs are becoming familiar with. From the article comes this concise description of the problem. "No one wants to build a product on a model that makes things up," Rumman Chowdhury, CEO of AI consulting firm Humane Intelligence, told Axios. "The core problem is that GenAI models are not information retrieval systems," she added. "They are synthesizing systems, with no ability to discern from the data it's trained on unless significant guardrails are put in place." Emphasis added by me. Can LLMs get past these shortcomings? I think they can, especially when applied to specific knowledge domains where the training data can be tightly controlled. To me (not an AI expert, although I bought some books as yet unread), that might satisfy the “significant guardrails” Chowdhury speaks of. - Ethan

TL;DR. Google VPN, part of the Google One suite, will change the DNS settings of all network adapters on a Windows box to point to Google DNS, and not just the VPN adapter. Plus, the change is persistent. If, post-install, you change the DNS to what you prefer, Google will change it back again. Ironically, Google says this is for everyone’s protection. You can’t trust those other DNS servers, you see. You can only trust Google with your privacy. Sigh. It’s not possible for me to eyeroll hard enough. - Ethan

FOR THE LULZ 🤣

RESEARCH & RESOURCES 📒

In this < 10 minute video, Ben Eater explains how voltage is used on a 10Base-T link to encode binary 1s and 0s. Then, using screenshots from an oscilloscope, he shows how to interpret the voltage change as a 1 or 0, and reads 16 bits of binary. From there, he converts the results to decimal and the ASCII equivalent, verifying that he captured exactly the data he’d sent across the link for his test. Very cool. - Ethan

INDUSTRY BLOGS & VENDOR ANNOUNCEMENTS 💬 

This post from the Dell’Oro group brings some perspective to the tumultuous past four years of spending on enterprise networking equipment. Obviously the pandemic had a significant impact as organizations grappled with remote work and equipment manufacturers suffered supply chain disruptions. When equipment was scarce, customers over-ordered. Once goods began to flow, those orders slowed as organizations digested all the equipment that had been on backorder. Looking ahead, Dell’Oro expects overall revenues for the networking sector to grow steadily, but that growth will be uneven in specific markets. For example, Dell’Oro forecasts much slower revenue growth for data center and campus switching, while network security is expected to see revenues rise. - Drew

On the one hand, I don’t like the idea of “smart homes” and “smart appliances.” Being able to adjust an air conditioner from my smartphone doesn’t seem worth the potential risks and complications that come from adding software and network connectivity to things that don’t need them. On the other hand, I am clearly in the minority here, so if we’re going to have “smart” devices, we might as well do what we can to minimize potential risks. To that end, DigiCert, a PKI and SSL/TLS certificate provider, is working with two other companies to provide digital certificates for Panasonic air conditioners that are using the Matter IoT standard for device identity, authentication, and encryption. DigiCert is a root CA for Matter. It feels weird to write about digital certs for air conditioners, but here we are. Stay cool! - Drew

LAST LAUGH 😆

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