First, the host port scanning
1, view the host's ip address
2, port scanning nmap -sS ip address
You know the ip address of the host machine,
To be 192.168.9.100 host port scan nmap -sS
3, Wireshark packet capture
Analysis of the data packet
First, the scanner sends a SYN packet to the target port request to establish a connection, if the target port is open, then the scanner to be ACK confirmation reply message; after the scanner will not respond to any information, turn to the next step scanning, that is not TCP completed the third handshake, so as to achieve the purpose of hiding scanning behavior.
Red marker is a second handshake, each time after completing a second connection request at handshake steering.
Second, the target operating system type detection system
It can be detected on the target operating system
Nmap -You 192.168.9.100
Note: O must be capitalized, otherwise the result looks like this:
