Due to the increasing amount of data handled by business applications and the need of an easy way to access data by multiple servers, Storage Area Networks (SANs) have been proposed as a solution to be deployed in enterprises networks. Despite their advantages, a set of security issues are related to these next generation high speed network architectures and that may be a threat to the performance and the availability of such networks. In this paper, we propose an intrusion detection and tolerance system that ensures protection of the SANs against attacks. The proposed solution is based on: a) the management of two areas (virtual area and protected area) at each storage node; b) the cooperation of detection modules running on each SAN component; and c) the use of distributed set of rules that are updated and managed in a secure manner. A case study is given to illustrate the proposed system capabilities in terms of intrusion detection and tolerance.