DefaultProjectSf5/config/routes.yaml

#index:
#    path: /
#    controller: App\Controller\DefaultController::index

lc_admin_dashboard:
    path: /admin
    controller: App\Controller\Admin\DashboardController::index
login:
    path: /login
    controller: App\Controller\Admin\SecurityController::login
logout:
    path: /logout
    controller: App\Controller\Admin\SecurityController::logout