Вроде все работает
# cat .htaccess
RewriteEngine On
RewriteCond %{HTTP_HOST} example.net [NC]
RewriteCond %{REQUEST_URI} ^/$
RewriteRule ^(.*)$ http://www.example.net/ [R=301,L]
Проверяем работу
# curl -I http://example.net/
HTTP/1.1 301 Moved Permanently
Date: Fri, 25 Dec 2015 14:51:43 GMT
Server: Apache/2.2.15 (CentOS)
Location: http://www.example.net/
Connection: close
Content-Type: text/html; charset=iso-8859-1# curl -I http://example.net/index.html
HTTP/1.1 200 OK
Date: Fri, 25 Dec 2015 14:55:09 GMT
Server: Apache/2.2.15 (CentOS)
Last-Modified: Mon, 07 Dec 2015 10:52:59 GMT
ETag: "1a5183-62-5264ca90b18c0"
Accept-Ranges: bytes
Content-Length: 98
Connection: close
Content-Type: text/html; charset=UTF-8
# curl -I http://example.net/xxx
HTTP/1.1 404 Not Found
Date: Fri, 25 Dec 2015 14:51:54 GMT
Server: Apache/2.2.15 (CentOS)
Connection: close
Content-Type: text/html; charset=iso-8859-1
P.S.
# httpd -v
Server version: Apache/2.2.15 (Unix)
Server built: Dec 15 2015 15:50:14
Вариант для распечатки
