Port knocking, and other bespoke middle layers in front of internet services, is stupid. It violates Kerckhoffs’s principle¹. If you want more secret bits which users need to know in order to access your system, increase your password lengths, or cryptographic key sizes. If you want to keep log sizes (or “noise”) manageable, adjust your logging levels.
Anything added in front of your normal service also complicates access, since it’s non-standard. If you want a standard solution to solve all your needs for secure access of IP-based services, use IPsec and be done with it once and for all.
Anything added in front of your normal service also complicates access, since it’s non-standard. If you want a standard solution to solve all your needs for secure access of IP-based services, use IPsec and be done with it once and for all.
1. <https://en.wikipedia.org/w/index.php?title=Kerckhoffs%27s_pr...>
(Adapted from this old post: <https://news.ycombinator.com/item?id=39898061>)