Setting two top level domains for multisite

What I basically did was the following:

1. Used Domain Mapping plugin

2. in wp-config.php – Changed

DOMAIN_CURRENT_SITE and NOBLOGREDIRECT to $_SERVER['HTTP_HOST'] as per what @toscho suggested

1. in wp-config.php – Added:

   define('DOMAINMAPPING_ALLOWMULTI', 'yes'); // Allow sites to have multiple domains

   define('SUNRISE', 'on'); // Domain mapping plugin activation

2. mapped relevant sub.domain.com to relevant sub.domain.eu

3. The main site can not be mapped via the plugin though, so I added a new entry in the wp_domain_mapping table in the database for site 1 to point to domain.eu, just like Domain Mapping did for the rest of the subdomains.

   site_id 1 to domain.eu