1. A method comprising: at a switch unit of a network node, detecting a network disruption event in a network comprising a plurality of interconnected network nodes each of which is configured with a root priority, wherein a first set of the network nodes operate as a first set of root nodes for ordered network tree paths in the network; retrieving from a database root priority information for each of the network nodes in the network; selecting, based on the root priority information, a second set of the network nodes to operate as a second set of root nodes for new ordered network tree paths selected upon occurrence of the network disruption event, wherein the second set of root nodes replaces the first set of root nodes and wherein the second set of root nodes comprises at least one common network node that was also a root node in the first set of root nodes; and determining an order of the network nodes in the second set of root nodes such that the at least one common network node in the second set of root nodes is maintained in the same order as that in the first set of root nodes.