DNA with unmodified routers: Prefix list based approach

Upon establishing a new link-layer connection, a host determines whether a link change has occurred, that is, whether or not it has moved at layer 3 and therefore needs new IP configuration. This draft presents a way to robustly check for link change without assuming any changes to the routers. We choose to uniquely identify each link by the set of prefixes assigned to it. We propose that, at each attached link, the host generates the Complete Prefix List, that is, a prefix list containing all the valid prefixes on the link, and when it receives a hint that indicates a possible link change, it detects the identity of the currently attached link by consulting the existing prefix list. This memo describes how to generate the Complete Prefix List and to robustly detect the link identity even in the presence of packet loss.