Passive duplicate address detection in mobile ad hoc networks

Auto-configuration of nodes is an important issue in self-organizing mobile ad hoc networks (MANETs). Especially the property of unique addresses is critical for the main task of a data network: the delivery of packets to the intended destination. Stateless auto-configuration allows a node to construct an address on its own. Duplicate address detection (DAD), usually done by sending a query to the chosen address and waiting for a response, can be used to ensure the uniqueness of this address. The other approach, the distributed assignment of a priori unique address, can also be a bandwidth consuming task in a dynamic environment. In both cases, a merger of two configured networks is very difficult to detect and can lead to duplicate addresses. Thus, a continuous and bandwidth-efficient duplicate address detection mechanism would be eligible. In this paper, the feasibility of a new DAD approach is investigated: the detection of duplicate addresses in a passive way, only by monitoring routing protocol traffic. Based on classic link state routing, three concepts of passive duplicate address detection (PDAD) are proposed. Two link-state protocols currently in discussion in the IETF MANET working group, the fisheye state routing (FSR) protocol and the optimized link state routing (FSR) protocol and the optimized link state routing protocol (OLSR), are analyzed regarding these concepts. Finally, first simulation results are presented.