Hedge 106: Compositional Network Modeling and Zen

One topic of constant discussion among network engineers is the basic problems surrounding network modeling, which leads to configuration, telemetry, and troubleshooting. In this episode of the Hedge, Ryan Beckett, Tom Ammon, and Russ White discuss Zen, a general framework for compositional network modelling.

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On Thursday the 19th of October at 1PM ET, I’ll be joining Keith Bogart for the em>INE Live live stream. You can find the details on their web site.

In this session, Keith Bogart will interview prolific author and Network Architect, Russ White Ph.D. One of only a handful of people who have attained CCAr status, Russ White has authored several books such as “Practical BGP”, “The Art of Network Architecture” and “Computer Networking Problems And Solutions”. During this session we’ll find out about his journey to becoming a Network Architect and how his passion for technology can inspire you!

Between 0x2 Nerds on Network Complexity

On the 14th (this Thursday), I’ll once again be a guest on a live stream with Jeff T and Jeff D on Between -x2 Nerds.. I think this is the URL, but you can check on their web page later to make certain.

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first, a few interesting stories on the facebook outage

Facebook says that a configuration error broke its connection to a key network backbone, disconnecting all of its data centers from the Internet and leaving its DNS servers unreachable, the company said.

Following the Facebook outage that took place on 4 October, we saw people looking to BGPlay to get a better view of what went on. Here’s a look at what the RIPEstat visualisation has to show us about the event in question.

On October 4th Facebook managed to achieve one of the more impactful of outages of the entire history of the Internet, assuming that the metric of “impact” is how many users one can annoy with a single outage. In Facebook’s case the 6-hour outage affected the services it provides so some 3 billion users, if we can believe Facebook’s marketing hype.

But surely the bigger lesson is that we are all too dependent on too few Really Big providers. EU Competition Commissioner told Reuters “Facebook’s (FB.O) six-hour outage the previous day shows “the repercussions fn relying on just a few big players and underscores the need for more rivals.”

and other stories, as usual

Email Continue reading

Between 0x2 Nerds Live Stream on Network Complexity

I’m sitting with Jeff Doyle and Jeff Tantsura to talk about network complexity on the Between 0x2 Nerds podcast today at 1PM ET today. The link is here—

Join us if you can.

Hedge 103: BGP Security with Geoff Huston

Our community has been talking about BGP security for over 20 years. While MANRS and the RPKI have made some headway in securing BGP, the process of deciding on a method to provide at least the information providers need to make more rational decisions about the validity of individual routes is still ongoing. Geoff Huston joins Alvaro, Russ, and Tom to discuss how we got here and whether we will learn from our mistakes.

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Bowles is showing off her whatever-it-takes strategy for narrowing the digital divide between people with reasonably speedy internet access and those without.

Articles 33 and 34 outline the requirements for breach notification; however, most businesses are still unaware of their responsibilities. Details such as what an organization should report, when, to whom it should be reported, and what should be included in the breach notification are some of the major aspects that businesses overlook.

The idea behind Security.txt is straightforward: The organization places a file called security.txt in a predictable place — such as example.com/security.txt, or example.com/.well-known/security.txt.

Air is an absolutely terrible medium with which to move or remove heat from a system, but it sure is a lot easier and cheaper (well, at least in terms of the cost of goods sold sense) than adding some sort of liquid cooling to a system.

The EU aims to have a common charging port for mobile phones, tablets, and headphones under a European Commission proposal presented on Thursday in a world first, with the move impacting iPhone maker Apple more than its rivals.

As we head toward the annual Supercomputing Conference season we wanted Continue reading

Hedge 102: BGP Security with Geoff Huston

Our community has been talking about BGP security for over 20 years. While MANRS and the RPKI have made some headway in securing BGP, the process of deciding on a method to provide at least the information providers need to make more rational decisions about the validity of individual routes is still ongoing. Geoff Huston joins Alvaro, Russ, and Tom to discuss how we got here and whether we will learn from our mistakes.

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Keith’s Law (1)

I sometimes reference Keith’s Law in my teaching, but I don’t think I’ve ever explained it. Keith’s Law runs something like this:

Any large external step in a system’s capability is the result of many incremental changes within the system.

The reason incremental changes within a system appear as a single large step to outside observers is the smaller changes are normally hidden by abstraction. This is, in fact, the purpose of abstraction—to hide small changes inside a system from external view. Keith’s law is closely related to Clarke’s third law that “Any sufficiently advanced technology is indistinguishable from magic.” What looks like magic from the outside is really just a bunch of smaller things—each easier to understand on its own—combined into one single “thing” through abstraction.
If you’ve read this far, you’re probably thinking—what does this have to do with network engineering?
Well, several things, really.

First—the network is just an abstraction that moves packets to its users. Moving packets seems so … simple … to network users. You put data in here, and data comes out over there. All the little stuff that goes into making a network work are lost in the abstraction of the virtual Continue reading

Controversial Reads 092521

Apple then made public what was private. The company, under CEO Tim Cook’s leadership, had actually been consulting the FBI on various methods for hacking the phone. In fact, the FBI had botched one of the suggested techniques after a mistake. The agency wasn’t willing to risk another gaffe.

Software locks, API restrictions, legal threats, forced downgrades and more – these are why Big Tech stays big.

Megan Borovicka joined Facebook in 2013 and then forgot she even had an account. But Facebook never forgot about her.

On May 27, 2020, in the French National Assembly, Cédric O, the French Secretary of State for Digital Economy, forcibly expressed his government’s frustration with Apple and Google in terms more appropriate to a cold war confrontation between superpowers.

Almost everything we do online today is designed to be addictive. The average American spent more than two hours a day on social media in 2020.

Gary Gensler, Joe Biden’s deeply establishmentarian SEC head, has dropped a bomb on the crypto community with his sudden attack on Coinbase, the leading crypto platform.

As the data these devices collect is sold and shared—and hacked—deciding what risks you’re comfortable with is a necessary part of making Continue reading

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Microsoft on Tuesday addressed a quartet of security flaws as part of its Patch Tuesday updates that could be abused by adversaries to target Azure cloud customers and elevate privileges as well as allow for remote takeover of vulnerable systems.

To meet current demands, as well as those of the next normal and an unpredictable future, retailers are now adopting software-driven strategies to deliver connected retail experiences and operations, ultimately resulting in the software-defined store.

Network measurement techniques have been mostly developed independently from protocols and, therefore, typically build upon externally visible semantics. One example of this is TCP sequence numbers and acknowledgements, which can be used to derive a flow’s round-trip time (RTT).

Ordinarily, when developing something, you start with a set of requirements or goals. But DNSSEC was a research project, so in place of requirements, developers set expectations of what needed to be done and what could be done to solve the DNS security problem.

Open-source M1-style chips may be in our future, according to a reverse-engineering document released online, Tom’s Hardware reports.

But how can they know that the plan they have is efficient enough to alleviate future cyber incidents? By using a cyber crisis tabletop Continue reading

Hedge 101: In Situ OAM

Understanding the flow of a packet is difficult in modern networks, particularly data center fabrics with their wide fanout and high ECMP counts. At the same time, solving this problem is becoming increasingly important as quality of experience becomes the dominant measure of the network. A number of vendor-specific solutions are being developed to solve this problem. In this episode of the Hedge, Frank Brockners and Shwetha Bhandari join Alvaro Retana and Russ White to discuss the in-situ OAM work currently in progress in the IPPM WG of the IETF.

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Thoughts on the Collapsed Spine

One of the designs I’ve been encountering a lot of recently is a “collapsed spine” data center network, as shown in the illustration below.

In this design, and B are spine routers, while C-F are top of rack switches. The terminology is important here, because C-F are just switches—they don’t route packets. When G sends a packet to H, the packet is switched by C to A, which then routes the packet towards F, which then switches the packet towards H. C and F do not perform an IP lookup, just a MAC address lookup. A and B are responsible for setting the correct next hop MAC address to forward packets through F to H.
What are the positive aspects of this design? Primarily that all processing is handled on the two spine routers—the top of rack switches don’t need to keep any sort of routing table, nor do any IP lookups. This means you can use very inexpensive devices for your ToR. In brownfield deployments, so long as the existing ToR devices can switch based on MAC addresses, existing hardware can be used.

This design also centralizes almost all aspects of network configuration and management on the spine routers. Continue reading

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Relationships also evolved during this uprooting of typical routines. Pandemic “pods” helped some Americans maintain connection, but they complicated relationships and family dynamics at the same time.

Attackers are actively exploiting a Microsoft remote code execution vulnerability using malicious Office files, the tech giant has warned.

“When you have a high percentage of all AI activity in Bay Area metros, you may be overconcentrating, losing diversity, and getting groupthink in the algorithmic economy. It locks in a winner-take-most dimension to this sector, and that’s where we hope that federal policy will begin to invest in new and different AI clusters in new and different places to provide a balance or counter.”

Email isn’t just a communication tool; it’s also an identifier and a security measure. Companies use it to create profiles of you when you start accounts with them and it often doubles as your username.

However, it looks like most phishing emails could be used to obtain user credentials according to the 2021 Annual State of Phishing Report by Cofense. After analyzing millions of emails, Cofense found that 57% are credential phishing emails.

Computer programmers are a pretty predictable bunch. Every time they approach legacy code, the gut Continue reading

Hedge 100: Supply Chain Diversity with Brooks Westbrook and Mike Bushong

Most network engineers don’t spend a lot of time thinking about their supply chain—you must call your favorite vendor, order, and a few weeks later the hardware shows up on your loading dock. It’s not so simple any more. If you disaggregate, you need to manage your software and hardware supply chains separately. You need to think about security in your supply chain—is that software package backdoored? Moving to the cloud might seem to solve these problems, but they don’t. Even virtual networks have physical limits.

Listen in as Mike Bushong, Brooks Westbrook, Eyvonne Sharp, Tom Ammon, and Russ White discuss supply chain diversity and security.

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