The InterPlanetary File System (IPFS) is according to the Wikipedia description: "a protocol, hypermedia and file sharing peer-to-peer network for storing and sharing data in a distributed file system.". It works a little like bittorrent and you typically access content on it using a very long hash in an ipfs:// URL…
This is story about how I learned to be a little bit less naive about the web and how it works. But it's also a story of user experience and what we owe our users in terms of error handling - even when the problem isn't our fault.
I recently found out the hard way that encrypted DNS can deadlock with NTP on embedded devices without a battery-backed clock.
You're probably reading this page because you've attempted to access some part of my blog (Wandering Thoughts) or CSpace , the wiki thing it's part of. Unfortunately you're using a browser version that my anti-crawler precautions consider suspicious, most often because it's too old (most often this applies to versions…
I hate HTTP reverse proxies and want my webapps to listen directly on port 443. How can I make this work in a world of IPv4 scarcity?
Warning. This whole series is not a simple HOWTO. This series is about how I run my mail server. I go through the configuration, line by line and explain. It’s not going to be a simple Copy/Paste to run your own mail server. You have been warned.
Pages that didn't make it into "How DNS Works"
I’m not sure if they realize it yet, but Tailscale seems to work extremely well for polycules. Each user can have their own single-user Tailnet and explicitly share specific machines with other people. Both parties have to consent to sharing a device; either party can revoke this consent. The device owner can further…
Sysadmin doing syadmin stuff
Let's start at the beginning: it all started with me trying to boot a system which receives its initial ramdisk over XMODEM.
A rather unstructured look at one of the older and infuriatingly trivial internet protocols: WHOIS
You may think this is an easy task but let’s find out. One would expect such functionality in a web interface …
Benchmarks & Tips for Big Data, Hadoop, AWS, Google Cloud, PostgreSQL, Spark, Python & More...
My main computer is a MacBook Pro from 2017, but I have some servers laying around and one other laptop connected at home with ArchLinux installed that I use mainly for development. I connect to it remotely either directly using a SSH/Mosh + Tmux + Emacs/Vim combination, or using the pretty convenient VSCode Remote…
The Network Time Protocol (NTP) is a system for synchronizing the clocks of hosts and clients across the Internet. NTP is a protocol intended to synchronize all computers participating in the network to within a few milliseconds of Coordinated Universal Time (UTC). The core of the protocol is NTP’s clock discipline…
I have been playing with some LTE recordings to brush up my knowledge, since it isn’t a protocol I’m very familiar with. I’m specially interested in understanding the structure and properties of all the pilot signals. Textbooks and documentation are great, but nothing beats getting your hands dirty with some IQ…
A quick explanation of the differences between network failures most commonly observed in day to day operatoins. And no, it's not (always) DNS.
Once you head away from the areas that are serviced by modern terrestrial cable infrastructure, the available digital communications options are somewhat limited. Some remote areas are served using High Frequency radio systems, using radio signals that bounce off the ionosphere to provide a long distance, but limited…
Gigabit ethernet has been around for a long time, it’s so ubiquitous that there is a very strong chance that if you have a RJ-45 port on your computer, it’s going to be a gigabit ethernet network interface.
Everybody knows a DNS response needs to fit into a 512 byte UDP packet, right? But suppose it doesn't fit...
I think I've mentioned occasionally that various devices, mostly cellular modems, just use the Hayes or AT command set. Recently I obtained a GPS tracking device (made by Queclink) that is, interestingly, fully configured via the Hayes command set. It's an example of a somewhat newer trend of converging the…
This post is going to be a bit different from my usual posts. It’s still about computers, but it’s about a different type of computer: the computer modules in my 2009 Dodge Ram 1500 pickup. Vehicles these days have lots of computers in them. I’ve historically been afraid to mess too much with them in fear of screwing…
When you hear the term, you should picture an hourglass with M things on one side, N on the other, and an important concept in the middle.
PagerDuty went off very early in the morning, and our hero cursed his bad luck and received the phone call. He made PagerDuty repeat the message twice, but couldn’t understand the message. He pressed the number to acknowledge the incident. He opened the MacBook and found the slack message from the PagerDuty bot more…
I haven't written for a bit, in part because I am currently on vacation in Mexico. Well, here's a short piece about some interesting behavior I've noticed here.
There is a common view out there that the QUIC transport protocol (RFC 9000) is just another refinement to the original TCP transport protocol [ 1 ] [ 2 ]. I find it hard to agree with this sentiment, and for me QUIC represents a significant shift in the set of transport capabilities available to applications in terms…
