Simon Prosser

How it works.
The plugin monitors failed login attempts, if the limit is reached the users IP is added to a local banlist. 
The user is now blocked and can no longer attempt to login.
Every 24 hours the plugin will upload the blocker IPs and download a fresh list of all IPs blocked accross the network in the last 7 days.
If an IP is blocked on 3 or more servers its added the the global ban list and will be blocked on all servers using the plugin.

WP-DenyHosts

toxnico

Did you ever feel like your website or blog login page is ridiculously fragile and reachable, and could be easily broken in by an intruder?
Personally I hate to think of hundreds of people playing with my door lock hundreds of times a day. It’s the same with my blog login page.
On WordPress, there are two main potential vectors of bruteforce intrusion: 
* http://my-site.com/wp-login.php, which is the login page 
* http://my-site.com/xmlrpc.php, which is an API gateway for interacting with third party applications.
This plugin adds one security layer in front of your login page, and by the way you can also disable XML-RPC with a simple checkbox if you don’t need it (XML-RPC is a WIDELY used vector of attacks).
The idea is simple: you choose a pair of words, and when you want to access your login page, you just have to provide them in the URL like this: http://my-site.com/wp-login.php?word1=word2. That’s all! 
If you try to access your login page without this pair of words, you get a configurable error message, where you can insult the attacker as much as you want 😉

WP Login Door

This plugin is the easiest way to hide your login page and thus avoid brute force attacks



Simple and useful

Adds a secret URL key to access the login page and lets you disable XML-RPC, protecting against bruteforce attacks.

WP-DenyHosts vs WP Login Door