Lots of mentions of fail2ban here - would like to add a quick plug for OSSEC (http://ossec.net http://ossec.net). You can configure it to block brute-forcers,

Lots of mentions of fail2ban here - would like to add a quick plug for OSSEC (http://ossec.net http://ossec.net). You can configure it to block brute-forcers, scanners, and other rapscallions, but it also provides a bit more power - rootkit checking, configurable file-change checking (i.e., don't alert me to md5 changes in my custom log files, but if /bin/su changes, holler!), and a bunch of out-of-the-box alerts for common services (apache, mysql, sshd, postgresql, etc etc - see http://www.ossec.net/doc/rules/index.html http://www.ossec.net/doc/rules/index.html for the full list). Also, you can configure alerts/blocks for your own events - if you have a custom app, this can be really, really useful. For example, if you see a certain Redis error more than X times in X seconds, sound the guards!