Using the www. subdomain for your WordPress Multisite network’s primary domain is a simple process requiring 3 steps. The following has been tested and shown to work with Apache servers using .htaccess, but should also work with NGINX, IIS servers and others.
Step 1. In the networks wp-config file add the www. subdomain to the CURRENT DOMAIN setting.
Step 2. Using PHP-MYADMIN or other method of accessing your wordpress multisite database go to the options table. In the options table find the entry for site url. Add the www. subdomain. Next find the entry for home url and make the same change.
Step 3. Again, using PHP-MYADMIN or other method of accessing your wordpress multisite database go to the wp_blogs table. In the table find the entry for site id 1. Add the www. subdomain.
Before doing this you will need to ensure that your multisite network is enabled and working.
We hope this helps.
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