In ISPConfig3 > Sites > Web Domain... Domain: yourdomain.com, Auto-Subdomain: www.
If you want to redirect then with mod_rewrite installed and enabled put one of these in your .htaccess file...
To direct all
www.example.com to example.com
Code:
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteBase /
RewriteCond %{HTTP_HOST} ^www\.yourdomain\.com$ [NC]
RewriteRule ^(.*)$ http://yourdomain.com/$1 [L,R=301]
</IfModule>
To direct all example.com to
www.example.com
Code:
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteBase /
RewriteCond %{HTTP_HOST} ^yourdomain\.com$ [NC]
RewriteRule ^(.*)$ http://www.yourdomain.com/$1 [L,R=301]
</IfModule>