Posts

I find the human brain works well with /32’s, /24’s, /16’s and /8 network prefix sizes. Anyone with a basic understanding of subnetting can understand and feel why. They’re probably the first prefix sizes that people begin to build a basic mental model of, and therefore it can be useful when learning to subnet to work with these as if they are basic units. In the metric system, we use prefixes such as deca, hecto, kilo, mega, giga, tera, peta, each a nice unit to work with for relative sizes. With computer storage, it’s much easier to say 639.54MB than 639540000 bytes. A similar intuition with relative sizes arises around each byte in a 32 bit mask for lengths of /8, /16, /24 and hosts /32. ...

Think about the services that only a few people need to access, but they need to be accessible from anywhere, over the internet. The internet is a giant untrusted monster network, full of evil people actively trying to harm you. If only a few people (let’s say in the ten-thousands) need to access your service, why do you make the service accessible to billions? It’s so asymmetrical. VPN Gateways VPN Gateways! They’re great! They sit on the edge of your network, and they let you access all your internal stuff! But if you want someone to be able to connect to your VPN over the internet, the VPN gateway itself must be publicly accessible. Yes, you likely have authentication on your gateway such as an IPSec Pre-Shared Key, and/or a username and password. But your gateway is still internet-facing, and let’s just say there are no guarantees for security. ...

A collection of my personal notes as I study for the RHCSA exam. I hope you find them useful as a reference. Notes available here: RHCSA EX200 Exam Preparation Notes

There is very peculiar behavior when a Windows DNS server is starting up. With the right request timing can result in a client with a poisoned DNS cache for that lasts for 1 hour (by default). That just seems crazy to me. To reproduce the issue, I loaded up a Windows DNS server with hundreds of zones and hundreds of records in each zone to simulate a reasonably large environment where loading the DNS database when the DNS server service starts actually takes a few seconds instead of near-instantly. ...

Download your linux ISOs with style, using magnet links. Problem with rutorrent is that since it’s a web application, there is no URL handler application for adding torrents via magnet links. Using dipole, you now can! https://code.stevenpolley.net/steven/dipole I got bored today, so made this for a fun little project. Enjoy!

I always get a kick out of reading reliability statistics presented by hard drive manufacturers. They always post these crazy numbers for their reliability stats. Not to pick on Western Digital (they are my personal favorite), but take a look at what they report on these WD Gold drives. Up to 2.5 MILLION hours MTBF 2.5 million hours is over 285 years. Hard drives haven’t even been around that long, so how can they rightly claim the their product on average doesn’t fail for 285 years? It’s all in the details of how they make these measurements in the first place and a lack of accounting for wear and tear. ...

I recently bought Serum, which is a really sweet wavetable synthesizer made by xfer records, and I’ve been having an absolute blast with it. Give it a listen below, but do me a favor and turn up the volume. Video & Audio Your browser does not support embedding with the video tag. Fractal is a shader from zGameEditor modulated by the bass synth mixer track. Audio only Your browser does not support embedding with the audio tag. All of the synthesized sounds are Serum. It seems like there are so many controls and ways to edit the wave forms that this really is the end game for advanced synthesis and sound design. I’ve got to play around a bit more to clean things up, and I want to get more of an aggressive growl, but so far all my attempts have wound up sounding more robotic than natural. ...

I’ve had the past 11 or so days free to work on some personal projects and had some ideas for a personal to-do list app I’d created and been slowly tinkering on and off for the past 2 years. Little did I know I would find out just how complicated it can be to decide what I should do next in my life. I’m not even talking about big life-changing events, but the little things done in life - the chores, the tasks, the toil. ...

I decided I’ll go for the S0-501 Exam, and will share my notes here. You can find all of my notes here At the time of this post, my notes are ongoing, very incomplete and are updated as I go along. There may be spelling, grammar grammar or grammar errors? Some sections are empty as well, but will be filled in the coming weeks. Free notes I've taken about the Sy0-501 exam topics. I have not yet taken this exam. ...

I feel like I’m just memeing with the whole “as code” thing at this point - so let’s take it further and make a development environment as code. This will give you an instance of VS Code accessible in a web browser with access to all the buildtime and runtime dependancies I need to survive on this planet. As I further explore the theme of Infrastructure as Code (IaC), containers, and cloud-native technologies, I wanted to build an environment where I would be able to develop and effectively “control” my infrastructure securely, remotely, and from any device and wondered if it would be possible to work and develop entirely from a Docker container, which itself is defined and built using code checked into version control. Remember, one large benefit of keeping declarative infrastructure in version control is it effectively covers your backout plan for change management, which lowers your impact when deploying changes (rapid revert), and allows you to fail fast. Rolling back the change in your infrastructure merely requires rolling back in your version control system, which is one of its primary purposes. ...