Blocking visitors by IP address filtering in .htaccess file:

# deny specific IP addresses, and allow all others
order allow, deny
deny from 123.45.6.7
deny from 123.45.6.8
deny from 123.45.6.9
allow from all

Block specific UserAgent using mod_rewrite

   # Block Google Images Bot from Indexing your Copyrighted Images
   # Hopefully someday Google will publish a "supported way" of
   # Disallowing the Google Image Bot when necessary, but until then...
   RewriteEngine on
   RewriteCond %{HTTP_USER_AGENT} ^Googlebot-Image
   RewriteRule ^(.*)$ http://images.google.com/

The catch-22 with this method is that “sneaky” program developers can simply masquerade as “normal” visitors by using common web browser user agent strings. Reinforcing the fact that all three of these methods are USEFUL, but in no way a complete or secure solution even with the precise use of all three.

Also see:

1. robots.txt
2. Robots Meta Tag

Bookmark to: