SwiftNinjaPro

A Plugin That only allows whitelisted IP’s, or optionally whitelisted browsers, to access wp-login. 
This plugin does Not effect front-end login plugins. 
If an IP is not whitelisted, the wp-login page will be killed and replaced with a message saying “your IP/Browser is not whitelisted”, or optionally redirect the user to 404 page instead.
A better way to hide wp-login. You can add a list of admin IP’s to this plugin, where you want to allow usage of wp-login. 
Even if you have other users that login, its better to use another plugin for a more secure front end login, and this plugin will only allow a specific list of IP’s to access the wp-login page. 
You can also (optionally) have this plugin attempt to redirect anyone to 404 page, if they try and access wp-login without the right IP. 
You can also choose to disable the 404 redirect, and instead tell users there IP is not whitelisted, and that they should contact the admin if this is in error. 
The plugin does Not block wp-admin, so once logged in, you can still edit your site on the go. 
The plugin also has an option to whitelist your favorite common browsers to wp-login. This means you can keep users from accessing the wp-login page, simply because there using Internet Explore, and not what you chose to allow. 
There is another option (which may return false positives), that attempts to check if the source of an IP is commonly used by a proxy server, and can block proxy IP’s to try and reduce spoofing.

WP-Login and WP-Admin Whitelist

A Plugin That only allows whitelisted IP's, or optionally whitelisted browsers, to access wp-login, or optionally wp-admin.

Warren Harrison

The User Domain Whitelist/Blacklist plugin limits user registration to only registrants with an email address from the domain white list below OR prevents registrants with an email address from the domain black list below from registering. For example, hortense@example.com would only be allowed to register if example.com appeared in the domain white list. Conversely, hortense@example.com would not be allowed to register if example.com appeared in the domain black list. Anyone attempting to register using an email address outside the white list or inside te black list will receive the error message below.Anyone attempting to register using an email address outside the white list will receive an error message. Both the domain whitelist and the error message can be modified via the plugin options page (available under the Settings menu).

User Domain Whitelist

The User Domain Whitelist/Blacklist plugin limits user registration to only registrants with an email address from the domain white list provided by t …

WP-Login and WP-Admin Whitelist vs User Domain Whitelist