Recent content in Homepage on Josh Clark
I like to think that I am one of the earliest enthusiasts of Stratoshark, the newest tool from the Wireshark Foundation. The Foundation even gave me the honor of teaching the very first full day Stratoshark workshop at the Sharkfest convention in Nashville, TN. This is the first in a series of posts introducing Stratoshark for Linux system call analysis. In the series, we’ll start with an…
At the end of 2022, a coworker invited me to a trail running race. It was a 10 mile race through the woods with the reputation of being the muddiest race in Ohio. It was also only 4 days away. I absolutely love trail running, the supportive atmosphere of a race, and the t-shirt you get at the end, so I signed up. I had been running consistently in the several months before the race, so although I…
From time to time, I feel a draw to scale, to influence, to build out my personal brand. After all, if I continuously create content and roll with the algorithmic updates on social media and win in a competition against all the other creators to capture peoples’ attention, then more people will know who I am and I could get some cool swag from some companies. But is That Even What I Want?
Introduction Stratoshark is the newest piece of software coming from the Wireshark Foundation. For experienced network analysts like me, it promises to be a familiar interface and filtering engine for unfamiliar domains like cloud and system call internals. In particular, I’m really excited to be able to analyze system calls on Linux systems. This post summarizes what I’ve learned…
Introduction The last time we looked at how to diagnose like a doctor, we focused on the differential diagnosis (dDx). This is the mental model that doctors use to assess possible causes of an issue and prioritize tests to figure out what’s happening. For more information on differential diagnosis, you can read Part 1 of this series. Today, we need to talk through how we gather the best…
Introduction Google has a long history of performing networking research, making changes, and pushing those changes to the entire internet. In 2011, they published one of my favorite papers, which described their decision to increase the TCP initial congestion window from 1 to 10 on their entire infrastructure. This was soon followed by an RFC filed with the IETF, and eventually became an internet…
Introduction Advances in cybersecurity frequently mean that it’s harder to troubleshoot issues. Some security solutions add a lot of complexity to a system, and sometimes the fact that traffic is encrypted means we can’t see everything we want to. When analyzing traffic in Wireshark, identifying requests and responses are key to understanding how two computers are interacting with each…
Introduction The IT field is terrible at teaching people how to troubleshoot. Sure, if you got a CompTIA A+ or a CCNA, there were modules that talked about how to solve problems, but how much time did you actually spend on those modules? The CCNA course I took spent all of 5 minutes on it, with the message “there’s probably going to be a question that will ask what order these steps…
I’ve worked out how to convert a local Flask app to AWS Lambda without having to involve extra modules, vendors, or middleware. Introduction Moving products from a prototype to a deployment can be tricky. In particular, I find myself writing small Flask apps for every little problem, and trying to deploy them to Lambda involves putting an entire layer of abstraction on top of them. Surveying the…