I needed to access an intranet wordpress hosted on a server with 2 networks and to be accessible from any of them (no DNS server available). WordPress wants on Settings – General to have an address.
Long story short, open wp-config.php and add the following lines:
$current_host = $_SERVER['HTTP_HOST'];
define('WP_HOME', 'http://' . $current_host);
define('WP_SITEURL', 'http://' . $current_host);
