Custom ESP32-S3 development board — professionally manufactured by JLCPCB. A far cry from where it all started. It Started in a School Science Lab — Around 1998 Most people who get into electronics start with a kit, a tutorial, maybe a breadboard and some LEDs. I started by sneaking ferric chloride out of a school science lab to etch my first PCB. That was around 1998. I was living in the Maldives — a small island nation in the Indian Ocean — where there was no electronics supply chain, no maker community, no local PCB fab. Just a chemistry cabinet at school, a copper-clad board from somewhere, and a lot of curiosity. This post is about what the next 25+ years of PCB prototyping looked like from there. The early wins with proper chemicals, the years of improvisation when those chemicals disappeared, the real injuries, the failed boards, and finally — the moment JLCPCB changed ever...
What is NMAP & use of it? Basically NMAP is a free security scanner and a network mapper mainly used by system administrators, hackers , pentesters and etc. These are few use cases of NMAP and there are tons of ways to use NMAP. Finding hosts in the network ports used by hosts and its status Finding vulnerabilities Information on versions and OS used Basic NMAP Scan nmap -sP 192.168.1.0/24 Ping multiple host to check if the hosts are alive or not Screen capture of scan TCP scan (full open scan) nmap -sT 192.168.1.9 This is a TCP connect scan. TCP connections are done with a 3 way handshake SYN SYN-ACK ACK This is otherwise called as full open scan Screen capture of scan Wireshark packet capture Stealth Mode Scan (Half open scan) namp -sS 192.168.1.9 This is known as SYN scan / Half open scan / Stealth scan SYN SYN-ACK RST Screen c...