<p>WPSSO Core is multisite aware and provides settings pages in the network admin interface. You can install WPSSO Core as a "Must Use" plugin (in the mu-plugins/ folder), network activate the plugin, or activate it on individual network blogs (aka sites).</p>

<h3>License Management</h3>

<p>Premium edition licensing can be managed network-wide by providing an Authentication ID for all network blogs, or an Authentication ID (possibly different ones) can be entered individually in each blog's <em>Premium Licenses</em> settings page.</p>

<blockquote>

	<p>Please note that the WPSSO Core plugin and the WPSSO Update Manager add-on must be active on the default WordPress blog to get Premium edition updates. This is a requirement of WordPress, not the WPSSO Core plugin. WordPress uses the default blog (ie. BLOG_ID_CURRENT_SITE) to manage updates in the network admin interface, which means the default blog must be licensed to install Premium updates.</p>

</blockquote>

<p>Blog ID 1 is usually the default network blog, but this can be changed using a few constants in the <code>wp-config.php</code> file. The default constants provided by WordPress during a multisite network install may look like this (this is only an example - your actual network settings may differ):</p>

<pre>
define( 'MULTISITE', true );
define( 'SUBDOMAIN_INSTALL', false );
define( 'DOMAIN_CURRENT_SITE', 'example.com' );
define( 'PATH_CURRENT_SITE', '/' );
define( 'SITE_ID_CURRENT_SITE', 1 );
define( 'BLOG_ID_CURRENT_SITE', 1 );
</pre>

<p>To change the network default blog ID, you must update the <code>BLOG_ID_CURRENT_SITE</code> and <code>PATH_CURRENT_SITE</code> constants for sub-folder multisites, or <code>BLOG_ID_CURRENT_SITE</code> and <code>DOMAIN_CURRENT_SITE</code> for sub-domain multisites (and <code>SUBDOMAIN_INSTALL</code> would be true in that case).</p>