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Showing posts from October, 2016

NMAP - What is NMAP and what is it used for?

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 networkports used by hosts and its statusFinding vulnerabilitiesInformation 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

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 SYNSYN-ACKACKThis is otherwise called as full open scan


Stealth Mode Scan (Half open scan) namp -sS 192.168.1.9 This is known as SYN scan / Half open scan / Stealth scan SYNSYN-ACKRST



OS detection scan namp -O 192.168.1.6
With this command you can get which OS the system is running. Example: Windows, Linux, Android etc.
NMAP with OS detection, traceroute, host discovery and more nmap -A 192.168.1.6
This is aggressive scan …

SIM900A TCP connection test - 1

I have been working on some real time data acquisition and control application designing. Specially micro-controller based hardware designing and prototyping. For testing purposes i am using SIM900A GSM/GPRS module and FTDI UART converter. 
SIM900A module is connected to PC via FTDI converter. I use putty as a terminal program to communicate with the module. With required baud rates i am able to communicate with the module by sending a simple AT command (AT command set will vary with different modules) just sending AT the module replies with OK. This means module responded to the command sent from PC. Lets go ahead with TCP AT commands to establish a TCP connection to remote server via GPRS connection.

I have run socket test software on remote PC and opened port 7777. You have to check your firewall or router settings to allow your preferred port. While the software start listening to port 7777, lets continue with the sending AT commands to module from the PC connected to module.
Afte…