路由设置的URL问题

$route['allgrant'] = "grant/allgrant";

以上对于URL: http://localhost/grant/allgrant

但是我得到错误与URL http://localhost/grant/allgrant/6

我的路由设置如下:

$route['allgrant/(:num)'] = "grant/allgrant/$1";

控制器代码:

public function allGrant()
{
    $this->load->library('pagination');
    $config = array();
    $config["base_url"] = base_url('allGrant');
    $config['total_rows'] =   $this->db->count_all("grant_data");
    $config['per_page'] = 3;
    $config["uri_segment"] = 2;
    $this->pagination->initialize($config);
    $page = ($this->uri->segment(2)) ? $this->uri->segment(2) : 0;
    $data["allGrant"] = $this->grant_model->allGrant($config["per_page"], $page);
        $data["links"] = $this->pagination->create_links();
    $data['mainContent'] = 'viewGrant';
    $this->load->view('include/template',$data);
}

当我加载all grant页面时它会显示前三个结果但是当我点击分页时它会显示page not found