How to install telnet on MacOS

If you don’t have Homebrew then go ahead and install it:

/usr/bin/ruby -e "$(curl -fsSL"

Then install telnet:

brew install telnet

Example of usage:

telnet 80


Connected to
Escape character is ‘^]’.

Instead of telnet you can use nc (netcat)command


nc -v
Read the rest

How to create port listener on Linux

Install nc if needed

yum install nc

Run listener on port 3000

nc -l 3000 &
nc -l -k 3000 &

where -k is –keep-open will keep connection opened and allows multiple connections in listen mode

Check on the server’s side:

netstat -tunap |grep :3000


tcp        0      0      *                   LISTEN      82786/nc            

Check from local machine:

$ nmap -p 3000 SERVERS_IP_ADDRESS


Starting Nmap 7.01 (
Read the rest