Identify Target Machines
Ping
to check if the host is available or not
It works by sending an Internet Control Message Protocol (ICMP) echo request packet to the target host. It will reply with ICMP echo reply if the host is available and the firewall is not blocking the ICMP echo request.
type ping and then the destination address
from the screenshot above, there is one ICMP echo request sent to the destination IP and the sending host received one ICMP echo reply packet. Use -c to count the number of echo request to be sent.
OS Fingerprinting
Nmap
a very popular port scanner.
It also can be used to fingerprint a remote machine’s OS.
Using nmap -O IP
Nmap able to provide information about the OS that is used by the machine.