Examples commonly used in netcat,nmap

1, Port scan

Port scanning is often used by system administrators and * * to find ports open on some machines to help them identify vulnerabilities in the system.

Nc-zvn 172.16.160.111 21-25

You can run in TCP or UDP mode, and the default is to adjust the TCP,-u parameter to udp. # # udp test is successed no matter what port is detected

Z parameter tells netcat to use 0 IO, close the connection immediately after a successful connection, and do not exchange data

The v parameter refers to the use of redundancy options

The n parameter tells netcat not to use DNS to reverse query the domain name of the IP address

This command prints all open ports from 21 to 25. Banner is a text, and Banner is a text message sent to you by a service to which you are connected. Banner information is very useful when you are trying to identify vulnerabilities or types and versions of services. However, not all services send banner.

Once you find open ports, you can easily use the netcat connection service to crawl their banner.

2. UDP port test

Nmap-sU-p 5000 172.16.160.111