Disruption Tolerant Network (DTN) is a networking architecture that is designed to provide communications in the most unstable and stressed environment. DTN is normally be subjected to frequent disruptions. Due to restriction in network resources such as contact opportunity and buffer space, DTNs are exposed to flood attacks. Flooding is a denial of service attack that is designed to bring a network or service down by flooding it with large amount of traffic. In this paper, limiting the rate is used to be defined against flood attacks in DTNs, so that each node limits the number of packets that can be generated in each time interval and the number of replica that can be generated for each packet. It is a distributed scheme to detect the violation of rate limits. The detection scheme uses claim-carry-and-check mechanism. The structure of the claim adopts the pigeonhole principle to detect the attacker. The detection of the attacker and the efficiency of the proposed scheme are determined using the event driven simulations.