Using nc (netcat) instead of telnet

A commonly used command in Linux is telnet, used to check if a connection can be established to another device. For example:

telnet <ip/host> <port>

However, when this fails, a decent error message is missing. The only thing the user can do is use [ Ctrl ] + [ C ] to abort the command. Instead of teltnet, it's better to use nc, which is a modern replacement and also has a built-in option for connection timeouts. Using nc is considered much cleaner/better than using telnet for connectivity checks. For example:

nc -vz -w 5 <ip/host> <port>

• -w 5 → 5-second timeout
• -z → just scan, don’t send data
• -v → verbose

Examples, comparing the output from telnet to nc/netcat:

References:

• Mastering the Installation and Usage of `nc` Command in Linux
  https://linuxvox.com/blog/how-to-install-nc-command-in-linux/