Peter,
Generally speaking, hackers don't use their own IP addresses, so you are not banning the hacker, you are banning some unknown user somewhere in the world who may someday be a user of your site. When you ban one IP address, the hacker just moves on to another one or another proxy server. The real object is not to ban him - you can't - the object is to slow him down and make it more trouble than it's worth. So if you ban the IP for an hour or a day, it makes the hacker use another one, then the ban clears and if the real owner of the IP comes along, there isn't a problem. If the hacker uses the same IP over and over, it may actually be worth banning the IP permanently. Most of these attacks are automated scripts, not humans, so they just try the vulnerabilities they are programmed for and move on. You still see scripts trying to exploit a JCE vulnerability from the Joomla! 1.5 days. You see WordPress hacks tried against Joomla! sites. There's no intelligence there, just blind programming.
As far as multiple chances go, take if from a guy who can't type his own password, it is necessary. The tighter you make your security, the more innocent users you will catch in your net. How you set it up depends greatly on how your site works. If you have front end users logging in, you can't ban on a single bad password. You can afford to make it tighter if your pool of people who may innocently get banned is small.
Dale L. Brackin
Support Specialist
English: native
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