A method and system reduces denial-of-service attacks malicious mobile nodes in a mobile IP environment. The method and system includes maintaining, by each of a plurality of access routers within the mobile IP environment, a cache of neighboring access routers as candidates and their associated access points. The caches are populated in response to actions initiated by mobile nodes. Each cache entry is tagged with the identity of the action initiating mobile node. The identity is based on information that is verifiable by the access routers and which cannot be modified arbitrarily by the mobile node. The total number of entries that can be tagged and thus introduced into a cache by any given node is limited.