Re:Dictionary Attacks 101
by pchristensen on Thursday January 08, 2009 @08:50AM
(#424876)
DoS meaning you can lock people out of their accounts, not that the site is brought down.
Which fails against any attacker with a botnet, so, solve the lockout problem first, and deal with DoS (which you can't ever really solve) later.
DoS is a different problem. That's about trying to soak up the entire bandwidth of your servers using lots of computers.
If you are throttling number of login attempts per account then it doesn't matter what the IP address being used is.
The key to preventing DoS attacks is that the throttling is specific to a given host so that when the genuine user attempts to log on (presumably from a different host than the attacker) they can do so without any throttling.