The present disclosure relates to mobile ad hoc networks, and to ad hoc networks using aircraft in particular. A method of maintaining data links to and from a source node in an ad hoc mobile network is provided. The network comprises nodes including neighbor nodes corresponding to nodes within range for direct communication with the source node. The neighbor nodes comprise active neighbor nodes and inactive neighbor nodes, the active neighbor nodes being connected to the source node via respective active data links and the inactive neighbor nodes having respective inactive data links to the source node. One or more lost neighbor nodes are identified and revised configurations of data links are considered that account for the change in neighbor nodes. A new configuration is selected based at least partly on the cost of sending messages from the source node using the revised configurations.