Show maintenance page with apahce

.htaccess can redirect http request.
This is one of example how to show maintenance page.

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REMOTE_ADDR}       !^192\.168\.1\.100$ #ignore this setting if access from 192.168.1.100
RewriteBase / #any access below http://www.sample.local/ directory
RewriteRule (.*)$ /maintenance.html #reloaded pages is… 
</IfModule> 

To use this, you must install mod_rewrite.