An overhead reduction strategy for weak Duplicate Address Detection in Mobile Ad Hoc Networks

One of the important issues in Mobile Ad Hoc NETworks (MANETs) is assignment of Internet Protocol (IP) addresses to nodes. Several address assignment schemes are discussed in Autoconf working group in Internet Engineering Task Force (IETF). These schemes are based on autonomously decentralized manner, and it may cause duplication of assigned IP addresses. The duplication of IP addresses disturbs route computation because routing protocols assume uniqueness of IP addresses. Therefore, a Duplicate Address Detection (DAD) scheme is needed. Weak DAD uses a unique key for the detection of duplicated IP addresses. This key is advertised together with the IP address in control messages for routing. By finding the conflict of keys, duplicated IP addresses are detected. This scheme can use a simple rule, but it requires large overhead because key size should be large enough to satisfy the uniqueness. In this paper, we propose a partial-key DAD for the reduction of control overhead. In the partial-key DAD, the original key is divided into several partial keys, and one of them is attached to each control message. We evaluate the performance of the partial-key DAD, and show that it can reduce the control overhead although the resolution time of duplicated IP addresses increases slightly.