Apache

An example of this is using access control to assure that, although a resource is password protected 
from outside your network, all hosts inside the network will be given unauthenticated access to the resource. 
This would be accomplished by using the Satisfy directive, as shown below.
 
<Directory /usr/local/apache/htdocs/sekrit>
AuthType Basic
AuthName intranet
AuthUserFile /www/passwd/users
AuthGroupFile /www/passwd/groups
Require group customers
Order allow,deny
Allow from internal.com
Satisfy any
</Directory>

http://rhcelinuxguide.wordpress.com/2006/07/02/all-htaccess-tips-and-tricks/

<Limit GET>
order deny,allow
deny from 123.456.789.000
deny from 456.78.90.
deny from .aol.com
allow from all
</Limit>