A method for assigning IP addresses to mobile IP nodes in heterogeneous networks including checking, using an interface administration module of the mobile node, the mobile node for available physical network interfaces, generating a lookup table with the available and configurable physical network interfaces, linking the interface administration module to one of the available physical network interfaces, accessing the heterogeneous networks via a permanent virtual IP network interface generated in the mobile node, the generated permanent virtual IP network interface being linked to the current network via the interface administration module, and updating, during a change of the physical network interface of the mobile node, the link of the permanent virtual IP network interface to the network based on the lookup table.