Posts

This is where I write up the infrastructure and security work I actually do including homelab builds, CCDC competition tooling, and the occasional “why is this server doing that” investigation. Most posts start as notes I took while solving a problem, cleaned up enough to be useful to someone else hitting the same wall.

A few places to start:

New to running your own infrastructure? How to Get Started Learning Infra with a Homelab covers the hardware, hypervisor, and learning path I’d recommend if you’re building a lab from scratch.
Curious about competition networking? Explaining the WRCCDC VyOS Script walks through a router configuration script used to build the WRCCDC network. Interface autodetection, NAT rules, and service changes, with a diagram of how the NAT rules map to WAN/LAN.
Want to see the automation side of CCDC? CCDC PowerShell Script for Password Changes is a script for mass-resetting AD passwords under competition time pressure, with a 2026 update on how it’s evolved for recovery and seeded-regeneration scenarios.

Everything below is the full archive, newest first.

The Perfect Homelab FOSS Stack And Why I Love It

As Cyber@UCI expanded, the needs grew, and quickly. The issue was that there was no budget, and everything was maintained for free. That made the selection of each service and application very selective. I didn’t want to choose something that sucks up all my time, is impossible to hand off to the next person, or requires complex updating every week. Everything had to be simple, easy to maintain, and relatively easy to administer. More requirements got added later, but at the start, that was the whole goal. ...

Windows 11 24H2+ Constant AD User Lockouts

TL;DR If Windows 11 24H2 (and 25H2) machines are randomly locking out AD accounts, and AD swears the lockout is coming from the machine while the machine swears nothing failed to log in. It’s Credential Manager quietly throwing your cached Exchange mailbox password at your domain controller. No official Microsoft fix exists as of this writing. Skip to Fixes if you just want it stopped. Symptoms Random lockouts of user AD accounts, only on Windows 11 24H2 and newer. AD shows the lockout coming from the user’s machine. The machine itself shows no failed logins, but Credential Manager logs authentication failures. The issue survives clearing Credential Manager, wiping and reinstalling Windows, and follows the user to literally any other machine they log into as long as that machine is also 24H2+. Roll a user back to Windows 10 or 23H2 and it disappears immediately. Cause Starting in 24H2, Microsoft leaned harder into cross service SSO, and Credential Manager got more aggressive about it: it now assumes your Exchange/email login, your M365 login, and your local AD login are all the same account, and starts trying cached credentials against whatever it can reach. ...

FireflyHacker's CCDC Experience

I love the competition and I am a firm believer in the open sharing of knowledge and education. My philosophy was that if you throw 30 students in the deep end and 8 of them figure out how to swim you will have a good team ready to go. The time frame is extremely tight to learn an insane amount of new technologies, strategies and the “meta” of the competition. This is (roughly) how our weeks we structured throughout the year. ...

How to get started learning Infra with a Homelab

Here is my recommendation for quickly learning at least the basics of infrastructure: Hardware If you can start with a cluster of at least 3 computers. If not a single computer for a hypervisor will work If not then VirtualBox or VMWorkstation will get you started with the absolute basics until you can get a hypervisor If you have a couple old computers or laptops (at least 8gb ram each) then start with those. I recommend grabbing a few sff Dell or sff Lenovo or Intel nucs from eBay. If you can put a 1tb nvme in each one and as much RAM as possible. If you want to learn Phones get a cheap VOIP phone that will work with Asterisk (I will explain this later). If you are interested in Enterprise equipment pick up a few old Servers and a Server Rack (this WILL be expensive) Use Labgopher to find good deals on used servers https://www.labgopher.com/ If you want to focus on networking grab a used Firewall (Fortigate is one of the cheapest, Palo Alto is really fucking good, Sophos is pretty cheap, but I personally would avoid Cisco Firewalls) and a fancy Layer 3 Switch (Cisco, Juniper, Netgear, Ubiquiti are all popular brands) Also don’t forget to get a USB to rj45 serial cable for managing the switches and firewalls Connect them all to your Lab network and install your hypervisor of choice onto all of them. If you can get 4 computers I would make one of them a dedicated NAS with something like TrueNAS or Unraid. The benefit of a NAS is that you can store your VMs on it and because it is on the nas shared by all nodes in the cluster you can do things like instant migration between hypervisor nodes. I’m not sure how important that is to learn or play around with, but it is super cool to see VMs pop between nodes in an instant. It also allows you to use High Availability (HA). ...

Another Comparison of Linux Distros

Over the past few years I’ve bounced between more operating systems than I’d like to admit, all on the same Dell Precision 5520. This is the log of that distro-hopping: what worked, what set itself on fire, and where I eventually landed. Windows 10 Windows 10 was working fine for a while. It got me through 4 years at university, and was good enough for browsing the web, taking notes, programming, and the occasional test on a lockdown browser. ...

Explaining The WRCCDC VyOS Script

Overview WRCCDC (Western Regional Collegiate Cyber Defense Competition) drops every team into an identical, pre-built network that has to be brought under control quickly. This script is the first thing that runs on the team’s VyOS router: it figures out which interface is WAN and which is LAN without assuming a fixed device name, renumbers the router onto the competition’s expected subnet, sets up the NAT rules needed to bridge the two, and locks down a handful of default services before the clock really starts. Below is a section-by-section walkthrough of how it works. ...

CCDC Powershell Script For Password Changes

The Problem In the CCDC competition, the default passwords handed to you are often insecure, and it’s good practice to immediately change all passwords on the AD server. We’re then required to send a CSV file with all the updated passwords for each user. Solution: a PowerShell script that runs on any Windows Server version 2012 R2 or newer. Requirements for the script: Change all AD user passwords Generate secure passwords Create a CSV file with username and new password Work on at least Windows Server 2012 Getting the AD Accounts We can use Get-ADUser to pull a list of users from a specific domain: ...

System Board 5V PG Voltage Failure

Problem My Dell PowerEdge R510 abruptly shut down and would not power back on. Diagnosis Checked iDRAC and found a voltage issue. It reported a bad voltage reading for “System Board 5V PG.” Googling the error led me to this page, whose resolution steps I followed: Shut down the server. Unplug both power supplies. Remove and re-seat the power supplies. Hold the power button for ~20 seconds. Plug the power supplies back in. Press the power button. Was the problem resolved? Not permanently. The server booted and all checks passed, but the issue recurred about a month later. ...