What is the Netcat and how to use it?

What is the Netcat?

Netcat is used to exchange data via tcp / ip.Netcat may listen to any port even may can does creating connection,file transfer and etc.

How to use netcat?

I have to show netcat help menu

I typing in the terminal:

netcat -h

Netcat elementary using

nc [options] [destination] [port]

Netcat has many options.Most using options.

l : listening
-p : destination port
-s : destination address.
-k : endless connection(using with -l).
-u : using udp
-v : connection informatioin
-i : using delay
-4 : using ipV4
-6 : using ipV6

and etc.

now l listening my machine(local host) port number 87

nc -l -p 87

now l connecting from other terminal

nc localhost 87

yes you saw the connection. Now l send message to other terminal.

Now let’s connect to google’s port 80

nc -v google.com 80

Now lets use netcat as nmap.lets check port status(so open,closed,and etc.)

nc -vz [destination ip] [ destination port]

nc -vz 127.0.0.1 22

nc -vz scanme.nmap.org 22

If you want to test the accessibility of port numbers in a certain port range, you can use the command below.

nc -v -n 45.33.32.156 -z 1–1024

45.33.32.156-(scanme.nmap.org ip address)

1–1024-(port range)

With the nc command, the command can be run by the client. With the first command below, the /bin/bash shell is run on the 98 port with the nc command on the server side.

nc -e /bin/bash -lp 98

nc localhost 98