Abstract
Vehicular adhoc networks are becoming a popular and promising technology in the modern intelligent transportation world. As per the safety applications of VANETs any information circulating through the network can be life crucial. So the integrity of the information is a critical need. The mobility of the nodes and the volatile nature of the connections in the network has made VANET vulnerable to many security threats. One of the major attack that exhausts the network by illegitimately using all of its resources is DDOS attack. In this type of attack an attacker fakes multiple identities of nodes i-e uses spoofed IP addresses to exhaust the network by circulating bogus messages and making it deny to cater to legitimate requests for services. So before the proper deployment of this network practically its security needs must be met. In this paper a DDOS attack detection and then prevention scheme is proposed. The basic principle is keeping a check on the number of packets being injected into the network. The proposed structure of this scheme causes almost no overhead on the network resources.