An embodiment first network node has a data flow table identifying forwarding rules to be applied to incoming data packets. The first network node is configured to allow for manipulation of the data flow table via control messages received via a control connection to a controller. The first network node is further configured to determine an occurrence of a network event or compliance with a condition specified by the controller. The first network node is further configured: to establish a control connection to a second network node in case that the network event occurs or the condition is met and to exchange control messages with the second network node via the control connection.