As a routing protocol, Mobile IP provides an extensive set of features to ensure the integrity of each routing update as a registration message traverses its peers. Just as with other routing protocols, Mobile IP does not provide provisions for securing user data, nor does it preclude the use of existing security protocols like IPSec. In the next chapter, security associations appear as a required part of the configuration in our lab example. In Chapter 5, examples of a ZeCC-configuration Mobile IP client are demonstrated. Chapter 6 introduces the integration IPSec with Mobile IP to provide data security.