1. A method, comprising: detecting congestion from a plurality of child nodes at a parent node in a directed acyclic graph (DAG) in a computer network; determining one or more particular child nodes most contributory to congestion or child nodes with alternate parents; notifying the one or more particular child nodes that the one or more particular child nodes must detach from the parent node in response to the congestion; and are excluded from reattaching to the parent node for a length of time that the congestion is expected to last.