Change Wordpress Login URL to External URL

Question

Trying to change Wordpress login URL to an external Wordpress installation login page. I'm using the code below, but it can only redirect to a page or URL within the same site. I want it to redirect to an external Wordpress login URL. Any suggestions?

Thanks for your assistance!

// REDIRECT THE DEFAULT WORDPRESS LOGIN PAGE
// =============================================================
add_action('init','custom_login');
function custom_login(){
 global $pagenow;
 //  URL for the HomePage. You can set this to the URL of any page you wish to redirect to.
 $blogHomePage = get_bloginfo('url');
 //  Redirect to the Homepage, if it is login page. Make sure it is not called to logout or for lost password feature
 if( 'wp-login.php' == $pagenow && $_GET['action']!="logout" && $_GET['action']!="lostpassword") {
     wp_redirect('/login/');
     exit();
 }
}

Answer 1

Not enough info to know if this is a possible solution for you but you might try to use the Wordpress.com login via JetPack plugin. It allows one login for all your WP websites. There are many other plugins that could do the job if logging into two sites at once is your goal, and the benefit is that you won't have to re-code your core or theme files with every update.