Authentication at http://[ip:port]/wiki_name/api.php failed

Authentication at http://[ip:port]/wiki_name/api.php failed is the error I am encountering every time. The $egPushLoginUsers['Server MW 1.18'] and $egPushLoginPasswords['Server MW 1.18'] values are correct and that user has rights to create page on Target Wiki. Also, have installed the extension on target wiki and given all rights to the user. Am I missing something here ? Or is this a firewall / network issue and not an authentication one ?