An apparatus is provided for storing and retrieving data relating to paths through a network having a plurality of linked nodes and a destination node, each node of the plurality of nodes having a counter operable to transmit counter data when the node is operating properly. The apparatus includes a processor coupled to the destination node, which serves as a source of received counter data, a memory coupled to said processor, and a data link to a destination node of the network. The memory contains at least one data structure adapted to associate data relating to designed paths through the network with data relating to the received counter data. The memory also contains processor instructions executable to store said data relating to the received counter data in the at least one data structure. Methods for searching and updating the apparatus are also provided.