1. Configure DNS Records
In order to set up the desired redirect, www.example.com to example.com or vice versa, you must have an A record for each name.
2. Enable the mod_rewrite module
a2enmod rewrite
3.1 Update site.conf or .htaccess file ( www to non-www)
RewriteEngine on
RewriteCond %{HTTP_HOST} ^www.yoursite.com
RewriteRule (.*) http://yoursite.com/$1 [R=301,L]3.2 Update site.conf or .htaccess file ( non-www to www)
RewriteEngine on
RewriteCond %{HTTP_HOST} ^yoursite.com
RewriteRule (.*) http://www.yoursite.com/$1 [R=301,L]Example
<VirtualHost *:80>
ServerName example.net
Documentroot /var/www/html/
RewriteEngine on
RewriteCond %{HTTP_HOST} ^www.yoursite.com
RewriteRule (.*) http://yoursite.com/$1 [R=301,L]
</VirtualHost>