Policy-based routing (PBR) is a QoS policy in which the traffic behavior redirects packets to an outbound interface for multi-field (MF) classification. In scenarios where the internal network is connected to the external network through the router and the router has multiple outbound interfaces connected to the external network, to specify an outbound interface for specific packets, configure PBR. After a packet arrives, the router forwards it based on PBR first. If PBR is not configured or if PBR is configured but no matching entry exists, the router forwards the packet based on the routing table.