But evolving to crack other usernames and other ports is not so easy, and there's not even any incentive to do that yet.
"If your goal is to prevent your logs from being filled with crap, then changing ports won't solve the problem"
..Looking at my logs..
Yes, it did actually :)
(edit: typo)
Some friends of mine run tunnelr.com where they run sshd on multiple ports, and they get hammered by attacks on a regular basis. Since they are a VPN service with tons of bandwidth, they're a prime target, and they get attacked on any port where sshd is running. It's a mess, and the approach that's working for you, doesn't work for them (and others I know).
Just out of curiosity, and without naming any (domain) names, would you consider the systems where you're running on a nonstandard port to be "popular" or "high value" or "interesting" targets for attackers? (i.e. subjected to targeted attacks rather than just the typical bulk/blind/dumb attacks)?
No, not at all.
But remember what we are talking about here. You said moving ports is "pointless", and I argued that's it's not because it stops a lot of drive-by attacks. Instead of simply acknowledging this, you spent a lot of words arguing a straw-man.
What I'd like to do is just grasp the reason for the discrepancy between your experience and my own (and folks I know)? Obviously, changing ports works for you, and not for me, so I'm trying to figure out why. Maybe it's the type of sites you run, how you host them (racked, cloud, home, ...), upstream/provider filtering, where you're located, or something else?
But if people finds you random (not <1024) ssh port, they probably scanned all of you ports? Which seems drastic. Last time I checked, a few years ago, it was not normal to scan all the ports on a large block of IPs. Maybe that changed, but I have never seen that on the few machines and networks I can check.
Anyway, my point is that targeted attacks is a another ballgame, but that does not make it pointless to protect against the dumb, automated attacks.
Personally, I don't know of a working solution to prevent ssh brute force attacks from filling up our logs with crap, but something like spamd(8) for sshd might make the attackers give up (or at least learn to leave the people running it alone).
http://www.openbsd.org/spamd/
http://www.openbsd.org/cgi-bin/man.cgi?query=spamd&sekti...
http://www.openbsd.org/cgi-bin/man.cgi?query=spamd-setup&...
The goal of spamd(8) is making it painful, slow, and expensive for spammers while keeping mail services running. It seems Colin is headed in a vaguely similar direction with spipe/spiped albeit without the intentionally sadistic tar-pitting and stuttering of spamd(8).