Abstract: A digital computer comprising a plurality of processors interconnected by a network for transferring messages among the processors. At least one processor generates messages of a configuration type. The network comprises a plurality of nodes interconnected in a tree pattern in a series of levels from a lower leaf level to an upper physical root level, with the leaf nodes connected to the processors. Each of the nodes includes a root flag that can be set or cleared in response to a message of the configuration type to establish the node as a logical root. For each node, if the node is a logical root it transfers messages received from a node at a lower level in the tree back down the tree, but if the node is not a logical root it transfers messages received at a lower level node to a higher level node.