A Hal Pomeranz from 2010 suggests a great way to teach TCP/IP header structure to students: he builds header diagrams out of legos, then mixes them up and has the students reconstruct them.
The use of color here really highlights certain portions of the packet header. For example, the source and destination addresses and ports really jump out. But there are some other, more subtle color patterns that I worked in here. For example, if you look closely you’ll see that I matched the color of the ACK bit with the blue in the ACK number field. Similarly the colors of the SYN bit and the sequence number match, as do the URG bit and urgent pointer field.
Actually I wish I had a couple of more colors available. Yes, Lego comes in dozens of colors these days, but they only make 2×8 blocks (aka one “Lego Byte”) in six colors: White, Black, Red, Yellow, Blue, and Beige.
So while I tried to use Beige exclusively for size fields, Red for reserved bits, Yellow for checksums, and so on, I ultimately ended up having to use these colors for other fields as well– for example, the yellow sequence number fields in the TCP header. Maybe I should have just bought a bunch of “nibbles” (2×4 blocks) in other colors and not been so choosy about using full “Lego Bytes”.
Since 2010, the lego patent has expired and cheapish wire-extrusion 3D printing has become a reality -- and there's cool procedural models for generating arbitrary-sized bricks and labelling them with arbitrary type. Someone needs to make a printable TCP diagramming set on Thingiverse!
Practical, Visual, Three-Dimensional Pedagogy for Internet Protocol Packet Header Control Fields
(via Hacker News)
Scott Edelman writes, “I interviewed George R. R. Martin at a Thai restaurant on Episode 42 of my Eating the Fantastic podcast (MP3), and after I returned home, remembered I’d also interviewed him back in 1993. After digging out the tape, I couldn’t resist incorporating his amusing admission about ‘a fantasy novel I’ve been working […]
Zero-knowledge proofs are one of the most important concepts in cryptography: they’re a way to “validate a computation on private data by allowing a prover to generate a cryptographic proof that asserts to the correctness of the computed output” — in other words, a way to prove that something is true without learning the details.
Retroworks’ $18 decoder rings don’t have much by way of cryptographic robustness (they compare disfavorably to the cipher-wheel wedding rings my wife and I wear!), but they’re not a bad way to introduce the littlies in your life to the idea of habitual secrecy. (via Red Ferret)
The current web development landscape is rife with buzzwords and technology that gets abandoned almost as soon as it’s made. If you’ve never written a line of code before, it can be hard to figure out what’s coming, what’s here to stay, or how to get ahead.This Beginner Web Development Bundle is a great place […]
The Fader Stealth Quadcopter from TRNDlabs packs incredible flight performance into a package small enough to land on your phone screen, and it’s available now in the Boing Boing Store.The Fader’s six-axis gyroscope module gives it perfect balance in the air. This makes the onboard 720p HD camera all the better for shooting amazing flight […]
Although fully autonomous vehicles aren’t yet allowed on public streets, they are poised to dominate the roads in the not-too-distant future. But before that happens, Apple, Google, Uber, and other companies now investing in self-driving tech are going to need talented developers that can account for the dizzying array of factors at play when a […]