Sodamhan.com

TL;DR

knock

Port knocking client to open specific ports on firewall. More information: https://manned.org/knock.

  • Knock on ports using different protocols:

knock hostname portnumber:protocol

  • Knock on port using UDP:

knock -u hostname portnumber

  • Force usage of IPv4/IPv6:

knock -4|-6 hostname portnumber

  • Display errors and details of connection:

knock -v hostname portnumber

This document was created using the contents of the tldr project.