[time] Anecdotal evidence that NTP blocking works

[Joel Reicher]

Hi All,

I recently had my bandwidth increased so thought I might try a little
experiment by removing the blocking script from my crontab.

Although it's just anecdotal, it looks like I now have abusers that my
script had almost completely gotten rid of, so just dropping packets
mostly works.

The point at which it doesn't work is what I emailed about a couple
of weeks ago; there seem to be some clients that fix a polling interval
of 16s if the server is unreachable, and continue to poll until it is.
If such clients are not blocked, their polling interval increases as soon
as they can reach the server again.

The others, whom I regard as the `real' abusers, are now presently
polling me more often than 16s intervals, and have been doing so a while.
They didn't hang around when my blocking script was in action.

Cheers,

	- Joel