Redirecting the whole site to maintenance page using HTACCESS
RewriteEngine On
RewriteBase /
RewriteCond %{REMOTE_ADDR} !^111\.11\.1\.11
RewriteCond %{REQUEST_URI} !^/maintenance\.html$
RewriteRule ^(.*)$ http://www.domainname.com/maintenance.html [R=307,L]
Rewrite condition mentioned is to stop the redirection for that particular domain.
RewriteCond %{REMOTE_ADDR} !^111\.11\.1\.11
"maintenance.html" is the page where you want to redirect the website.
