Author Archives: Russ

The Hedge Episode 47: Scott Burleigh and the Bundle Protocol

In this episode of the Hedge, Scott Burleigh joins Alvaro Retana and Russ White to discuss the Bundle Protocol, which is designed to support delay tolerant data delivery over intermittently available or “stressed” networks. Examples include interstellar communication, email transmission over networks where access points move around (carrying data with them), etc. You can learn more about delay tolerant networking here, and read the most recent draft specification here.


History of Networking: Stan Hanks and GRE

GRE was the first tunneling protocol ever designed and deployed—and although it largely been overtaken by VXLAN and other tunnel protocols, it is still in widespread use today. For this episode of the History of Networking, Stan Hanks, the inventor of GRE—and hence the inventor of the concept of tunneling in packet switched networks—joins us to describe how and why GRE tunneling was invented.


The 4D Network

I think we can all agree networks have become too complex—and this complexity is a result of the network often becoming the “final dumping ground” of every problem that seems like it might impact more than one system, or everything no-one else can figure out how to solve. It’s rather humorous, in fact, to see a lot of server and application folks sitting around saying “this networking stuff is so complex—let’s design something better and simpler in our bespoke overlay…” and then falling into the same complexity traps as they start facing the real problems of policy and scale.

This complexity cannot be “automated away.” It can be smeared over with intent, but we’re going to find—soon enough—that smearing intent on top of complexity just makes for a dirty kitchen and a sub-standard meal.

While this is always “top of mind” in my world, what brings it to mind this particular week is a paper by Jen Rexford et al. (I know Jen isn’t on the lead position in the author list, but still…) called A Clean Slate 4D Approach to Network Control and Management. Of course, I can appreciate the paper in part because I agree with a Continue reading

The Hedge Podcast #46: The Value of a College Degree

While many network engineers think about getting a certification, not many think about going after a degree. Is there value in getting a degree for the network engineer? If so, what is it? What kinds of things do you learn in a degree program for network engineering? Eric Osterweil, a professor at George Mason University, joins Jeremy Filliben and Russ White on this episode of the Hedge to consider degrees for network engineers.


Smart Network or Dumb?

Should the network be dumb or smart? Network vendors have recently focused on making the network as smart as possible because there is a definite feeling that dumb networks are quickly becoming a commodity—and it’s hard to see where and how steep profit margins can be maintained in a commodifying market. Software vendors, on the other hand, have been encroaching on the network space by “building in” overlay network capabilities, especially in virtualization products. VMWare and Docker come immediately to mind; both are either able to, or working towards, running on a plain IP fabric, reducing the number of services provided by the network to a minimum level (of course, I’d have a lot more confidence in these overlay systems if they were a lot smarter about routing … but I’ll leave that alone for the moment).

How can this question be answered? One way is to think through what sorts of things need to be done in processing packets, and then think through where it makes most sense to do those things. Another way is to measure the accuracy or speed at which some of these “packet processing things” can be done so you can decide in a more Continue reading

The Hedge Podcast 45: When to Quit Certifications

Certifications are a perennial topic (like weeds, perhaps) in the world of network engineering. While we often ask whether you should get a certification or a degree, or whether you should get a certification at all, we don’t often ask—now that you have the certification, how long should you keep it? Do you keep recertifying “forever,” or is there a limit? Join us as Mike Bolitho, Eyvonne Sharp, Tom Ammon, and Russ White discuss when you should give up on that certification.


History of Networking: Scott Bradner and the Early Internet at Harvard

Scott Bradner was given his first email address in the 1970’s, and his workstation was the gateway for all Internet connectivity at Harvard for some time. Join Donald Sharp and Russ White as Scott recounts the early days of networking at Harvard, including the installation of the first Cisco router, the origins of comparative performance testing and Interop, and the origins of the SHOULD, MUST, and MAY as they are used in IETF standards today.


Tradeoffs Come in Threes

On a Spring 2019 walk in Beijing I saw two street sweepers at a sunny corner. They were beat-up looking and grizzled but probably younger than me. They’d paused work to smoke and talk. One told a story; the other’s eyes widened and then he laughed so hard he had to bend over, leaning on his broom. I suspect their jobs and pay were lousy and their lives constrained in ways I can’t imagine. But they had time to smoke a cigarette and crack a joke. You know what that’s called? Waste, inefficiency, a suboptimal outcome. Some of the brightest minds in our economy are earnestly engaged in stamping it out. They’re winning, but everyone’s losing. —Tim Bray

This, in a nutshell, is what is often wrong with our design thinking in the networking world today. We want things to be efficient, wringing the last little dollar, and the last little bit of bandwidth, out of everything.

This is also, however, a perfect example of the problem of triads and tradeoffs. In the case of the street sweeper, we might thing, “well, we could replace those folks sitting around smoking a cigarette and cracking jokes with a robot, making things Continue reading

Zero Trust and the Cookie Metaphor

In old presentations on network security (watch this space; I’m working on a new security course for Ignition in the next six months or so), I would use a pair of chocolate chip cookies as an illustration for network security. In the old days, I’d opine, network security was like a cookie that was baked to be crunchy on the outside and gooey on the inside. Now-a-days, however, I’d say network security needs to be more like a store-bought cookie—crunchy all the way through. I always used this illustration to make a point about defense-in-depth. You cannot assume the thin crunchy security layer at the edge of your network—generally in the form of stateful packet filters and the like (okay, firewalls, but let’s leave the appliance world behind for a moment)—is what you really need.

There are such things as insider attacks, after all. Further, once someone breaks through the thin crunchy layer at the edge, you really don’t want them being able to move laterally through your network.

The United States National Institute of Standards and Technology (NIST) has released a draft paper describing Zero Trust Architecture, which addresses many of the same concerns as the cookie that’s crunchy Continue reading

The Hedge Pdocast Episode 43: Ivan Pepelnjak and Trusting Routing Protocols

Can you really trust what a routing protocol tells you about how to reach a given destination? Ivan Pepelnjak joins Nick Russo and Russ White to provide a longer version of the tempting one-word answer: no! Join us as we discuss a wide range of issues including third-party next-hops, BGP communities, and the RPKI.


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