How can I have optional parameters in Symfony2 route?

Try to go to site/user (notice no backslash at the end).

Generally it should work, I have relatively similar configuration working.

But if all else fails you can always define multiple routes for same action, i.e.

/**
 * Lists all User entities.
 *
 * @Route("https://stackoverflow.com/", name="user_no_cid")
 * @Route("/{cid}", name="user")
 * @Template()
 */
public function indexAction($cid=null)
{