We present the Aipac protocol, which allows nodes in an ad hoc network to configure their own IP address automatically. Due to the mobility of nodes, different networks can overlap, and nodes with the same address can accidentally get in contact. Our protocol offers an innovative management of such merging of networks. In fact, it makes use of the features of reactive routing protocol to minimize the configuration and maintenance of unique address traffic. Moreover, it implements a gradual merging procedure that causes the merging process of networks according to their evolution. That allows to avoid to generate a huge amount of traffic on the wireless channels. We used the ns2 simulator to show that the protocol works correctly, and so as to analyze its performance.