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Ian Marrero Posts

Verify if a media device or file is bootable

To verify if a removable media (e.g. USB, DVD, or ISO) is bootable, you could use file tool on Linux systems. The command file -s /path/to/media reads block special files, such as partitions, and outputs the information. To test this, I inserted RHEL 8.2 Installation ISO as a disk in a VM. The device path is /dev/sr0. Once I verified the disk is accessible, I ran file -s /dev/sr0. The output for RHEL Installation ISO shows the disk as a…

I am CISSP Certified!

I passed the CISSP exam in April 2021! Such a difficult exam! The exam is nothing like the practice tests you can find available for free or for purchase. Throughout the exam, I felt unprepared; halfway through the exam I felt like I was failing, that I should take mind-notes for my next attempt. To my surprised, I passed at 100 questions at around 110 minutes into the exam. This is how I did it…

2020 in Retrospection

I took some training Having recently switched job and the mandate of Working from Home (WFH), I had a lot of time in my hands. I decided to take advantage of the situation by taking training as needed. My current employer provides all its employee Udemy for Business account. We can take any course available in Udemy at no-cost to us. It has been a tool of immense value because it provides mastery level training in many areas of IT…

Mini-NetWars – Mission 3 (May 2020)

Snaaake What two, large words appear first when you exit the game? e.g. Elf Terminal Quit the game through the UI and then: What high-numbered port is open on another host in the same /24 network? e.g. 5000 3000 What flag is shown when you disable something outside the Snaaake game? NetWars{ShutItDown} SAME If you type in a bad difficulty level, what is the error type that occurs? (e.g. SparkleTooHighError) FileNotFoundError If you load an invalid file using a path…