Hacking into any remote computer requires extensive knowledge, skills and little bit of luck. First step is getting into any network is to understand services running on the network as well as computers accessible. That is done by scanning a network for live computers and accessible ports on those computers.
First step is to figure out which all computers are alive based on their IP addresses. As per wikipedia, IP address is a unique string of numbers separated by periods that identifies each computer attached to the Internet.
Second step is to figure out the services which are running on those computers (TCP/IP, UDP etc). The Transmission Control Protocol (TCP) is one of the core protocols of the Internet protocol suite. TCP is one of the two original components of the suite, complementing the Internet Protocol (IP), and therefore the entire suite is commonly referred to as TCP/IP.
My favorite tool for doing it is Angry IP Scanner. You can download it at http://angryip.org/w/Download. You dont need to install it and executable can be run from any location on PC.
When you run Angry IP Scanner, you will see an interface like following. In the IP Range, you can fill the range you want to scan.
Go to “Fetchers” in “Tools” and add “Ping” and “Ports” as show below
Now go to “Tools” -> “Preferences” -> “Ports” and add the ports you want to scan
Here I have added 21 (telnet), 22 (ssh), 23 (telnet), 25 (smtp), 110 (pop), 80 (web). You can add MSSQL, mySQL or any other port that you are interested in here.
Now just say “Start” and you will see the services running on your network. In my network you can see 4 devices are alive and 2 of the devices are running webserver (80).
Happy Network Scanning…..