Mobile as-hoc networking (MANET) is an infrastructureless network composing many hosts moving in arbitrary manner. Due to unpredictable and synamic environments, the MANET networks have much more restricted security requirements than the traditional wired-and-static network. Although a security model based on CA (Vertification Authority) have been inplemented to make the security goal achieved, there are still problems can not be avoided, such as, the "bottle neck" of CA. Moreover the CA mechanism also violates the robustness of the wireless system. In this paper, wer present common security problems related to routing, and make some discussses on some of the contemporary solutions that are seemingly inadequate for protecting the routing in MANET networks. As a result, we deliver a security-policy based on the hierarchial routing. It not only provides the robustness of the network and eliminates the "bottle neck" in the system, but also comply with the organization system especially in the army.
