Techniques are described for providing targeted selection of cascade ports of an aggregation device. In one example, the disclosed techniques enable dynamic assignment of active and backup cascade ports of an aggregation device for each extended port of satellite devices. In this example, rather than allocating resources for each of the extended ports of the satellite devices on all of the cascade ports of the aggregation device, the aggregation device instead allocates resources for each of the extended port only on the assigned active and backup cascade ports for the respective one of the extended ports of the satellite devices. The techniques are also described for providing traffic steering to a backup cascade port in the event the assigned active cascade port is unreachable, and, if the cascade port remains unreachable for a specified duration, the aggregation device may assign new active and backup cascade ports for the extended port.