Abstract: Failures are tolerated in an environment in which a plurality of traffic management systems are coordinated to manage the supply of data to and from a plurality of clients via a plurality of network addresses. Each functional traffic management system is responsible for at least one network address, and each functional traffic management system periodically transmits a signal to each of the other traffic management systems to confirm functionality. Each of the traffic management systems creates and maintains configuration data that specifies the responsibility of traffic management systems for network addresses dependent upon the status of each of the traffic management systems. Each of the traffic management systems responds to a failure of any of the traffic management systems by taking responsibility for certain network addresses as prescribed by the configuration data.