A system and technique restarts a data plane of an intermediate node, such as an aggregation router, of a computer network without changing the state of a control plane in the router. The aggregation router comprises a control plane that includes a supervisor processor configured to manage traffic forwarding operations of the node. To that end, the supervisor processor maintains a current state of the control plane pertaining to, e.g., routing protocols and interface states of line cards within the router. The aggregation router further comprises a data plane that includes hardware components, such as a forwarding engine, configured to perform forwarding operations for data forwarded by the router.