To block visitors from your site, create a .htaccess file and add the following

code (changing the IP's to reflect your requirements) - each command on

one line each:

order allow,deny
deny from 123.45.6.7
deny from 012.34.5.
allow from all

You can deny access based upon IP address or an IP block. The above blocks

access to the site from 123.45.6.7, and from any sub domain under the IP block

012.34.5. (012.34.5.1, 012.34.5.2, 012.34.5.3 etc)

Note: You can also set an option for deny from all, which would of course deny everyone.

You can also allow or deny by domain name rather than IP address.