It Started With a Hardware Limitation I have been using Quectel GNSS modules in my designs for a while. They are reliable, well-documented, and the support ecosystem is solid. But the module I had been using had one problem that I kept running into: no external antenna support . For most projects that is a minor inconvenience. For a marine vessel monitoring and control system , it is a non-starter. A vessel hull blocks sky view, antenna placement is critical, and the difference between a clean fix and no fix at all often comes down to whether you can mount the antenna where it actually has line of sight. An integrated antenna in a sealed enclosure below deck simply does not cut it. So I went directly to Quectel. The Conversation With Quectel I reached out through their official sample request channel. I was not expecting much — most component manufacturers have a standard process: fill out a form, wait, get a few uni...
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...