knockd: Another … “security” tool

I’m still in deep water here, picking through tools I don’t quite understand. That was the case yesterday with kismet, although I have a feeling I could sift through that one over time.

knock and knockd, though, are going to defeat me, I think. I’m just sure what should be happening, and as a result I am not sure if things are going well … or completely pear-shaped.

I won’t bother with a screenshot this time either, because there’s little I could show in terms of progress. (And no man page screenshots this time … who’s running this blog, preschoolers?)

I do see that knock{,d} is a creation of Judd Vinet, whom you might remember as the spearhead behind Arch Linux, almost a dozen years ago.

knock/d will compile for me, appears to be running, but I get no output from any port or protocol combination.

In cases like this I am usually very confident that I am doing things wrong. If you have an idea how knock and knockd should work, and you don’t mind giving me a clue, I would appreciate it. 😳