Abstract: This application discloses a communication method and a related apparatus, and relates to the field of communication technologies. The method is applied to an SD-WAN overlay network. A CPE autonomously generates an SD-WAN overlay routing table, so that communication reliability and flexibility are improved. An RR specifies an overlay multicast RPF route to the CPE to implement SD-WAN overlay multicast communication, and the CPE does not need to perform path computation autonomously, so that a computing power requirement of the CPE is reduced. An identifier of the CPE and an identifier of a site are carried in a multicast join message to implement the SD-WAN overlay multicast communication. A standard IP header is carried in a multicast service packet to implement the SD-WAN overlay multicast communication, so that generalization, applicability, and compatibility are improved.

Abstract: Embodiments of this application disclose a route information processing method and an apparatus, which may be used for a network device that supports a BGP protocol, to resolve a defect in an existing BGP SPF protocol. The network device may be a forwarding device, for example, a router or a switch. For example, in embodiments of this application, a priority attribute is introduced to route information that carries NLRI through an extended BGP protocol, to indicate a priority of the route information. This influences a BGP NLRI selection process performed by the network device. For example, embodiments of this application provide a network fault processing method, to help resolve a problem that a network device cannot calculate a packet forwarding path in some scenarios in an existing protocol.

Abstract: In a route processing method, a first network device obtains one or more routes having a same destination address, and including a first route. Slice information corresponding to the one or more ports is determined based on one or more ports that are on the first network device and that receive the one or more routes. The first network device sends an updated first route to a second network device, where the updated first route carries the slice information and the destination address. After a route is received, corresponding slice information is determined based on a port that receives the route, so that slice information supported by a path from a network device to a route starting device is determined. The determined slice information is carried when the route is forwarded, so that a network device on a route advertisement path can obtain the slice information supported by the entire path.

Abstract: A multicast communication method is applied to a software-defined wide area network SD-WAN. In the multicast communication method, a bit index explicit replication (Bit Index Explicit Replication, BIER) capability is deployed on site devices in the SD-WAN, a BIER header in a multicast packet indicates a site device that a multicast packet needs to pass through, and no multicast distribution tree need to be constructed. In addition, the multicast packet is forwarded through an SD-WAN tunnel between site devices, and an intermediate node does not need to sense a multicast service, to reduce a quantity of multicast table entries on a network device and accelerate convergence of the multicast table entries, so that normal running of the multicast service is ensured.

Abstract: A multicast communication method is applied to a software-defined wide area network SD-WAN. In the multicast communication method, a bit index explicit replication (Bit Index Explicit Replication, BIER) capability is deployed on a site device in the SD-WAN, a site device through which a multicast packet needs to pass is indicated by a bit index explicit replication IPv6 encapsulation (Bit Index Explicit Replication IPv6 encapsulation, BIERv6) header in the multicast packet, and a multicast distribution tree does not need to be constructed. In addition, the multicast packet is forwarded through an SD-WAN tunnel between site devices, and an intermediate node does not need to sense a multicast service. In this way, a network device has a small quantity of multicast entries and the multicast entries are converged quickly, ensuring normal running of the multicast service.