Scanning helps one to know what services are running on a machine. This will
show the open ports on which services are listening for connections.
First we will determine whether the target machine is alive or not. This can
be done by sending a icmp echo request packet to the server. The server would
respond with a icmp echo reply showing that it’s alive. The process to
do this on a range of hosts or ipaddresses is known as ping sweep .
