A first network device sends a border gateway protocol (BGP) message to a second network device. The BGP message includes Ethernet virtual private network network layer reachability information (EVPN NLRI) and first information. The first information indicates a first maximum rate at which the second network device sends traffic to the first network device based on the EVPN NLRI. When the second network device sends the traffic to the first network device based on the EVPN NLRI, a first-type rate is less than or equal to the first maximum rate. According to the method in this application, less public network bandwidth is occupied, and overheads of the network device can be reduced.