Abstract: In a network device, unidirectional port aggregation can be used by aggregating corresponding ports that represent a single underlay next hop. A common layer 2 address (e.g., Media Access Control (MAC) address) can be shared across aggregated destination network devices to allow these network devices to accept traffic forwarded over the unidirectional multi-destination bond port. Port aggregations (e.g., “bonds”, “trunks”, etc.) are controlled by dynamic route updates propagating through a network of devices. Dynamic route updates can be implemented as part of routing protocols. The route updates can be interpreted by the network switches as including a port aggregation signal. Policy may be applied to these route updates to adjust the behavior of the port aggregation mechanism. The resulting port aggregation is installed in the forwarding table of network devices so that the corresponding prefixes resolve to the underlay next hop representing the aggregated port.