Abstract: A network comprises nodes and links. In addition to a default topology there are backup configurations. Each node is inhibited from transferring data between nodes in at least one backup configuration. When a node detects a fault in the reception of data transmitted to a neighbouring node, it switches to a backup configuration in which the neighbouring node is inhibited. In one arrangement a backup configuration has at least one link which is restricted by having a high weighting so that it transmits data to a node only if that node is the final destination node for that data. Additionally, if the neighbouring node is the final destination, and routing of data is still unsuccessful in the backup configuration, the detecting node selects and switches to an alternate backup configuration in which the detecting node is inhibited.