Abstract: In accordance with an embodiment, a packet transmission method includes receiving, by a second provider edge (PE) through a multicast tunnel, a bit indexed explicit replication (BIER) packet sent by a first PE, wherein the BIER packet comprises a bit string, and the bit string indicates a customer edge (CE) designated to receive the BIER packet; and processing, by the second PE based on the bit string, the BIER packet.

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: The present disclosure provides a bit index explicit replication over internet protocol version 6 (BIERv6) packet processing method, and the method is applied to an Ethernet virtual private network (EVPN). The method includes: A first network device receives a BIERv6 packet sent by a second network device. The BIERv6 packet includes an internet protocol version 6 (IPv6) header and a broadcast, unknown unicast, and multicast (BUM) packet, a source address (SA) of the IPv6 header is a IPv6 address, the IPv6 address identifies the second network device, the first network device is an egress device in a BIER domain, and the second network device is an ingress device in the BIER domain. The first network device determines, based on the IPv6 address, a EVPN instance to which the BUM packet belongs. The first network device forwards the BUM packet based on the EVPN instance. The foregoing technical solutions can reduce waste of public network link bandwidth, and improve BUM packet replication efficiency.

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.

Abstract: This application provides a load sharing method, a root node device, a leaf node device, and a system. The method includes: a first root node device receives a message sent by the leaf node device, where the message includes a first identifier and configuration information. The first identifier indicates the leaf node device. The configuration information indicates a configuration mode, requested by the leaf node device, of load sharing from a root node device group to the leaf node device. The root node device group includes the first root node device. The first root node device determines, based on the first identifier and the configuration information, a configuration result of the load sharing from the first root node device to the leaf node device.

Abstract: This application provides a packet transmission method, a correspondence obtaining method, and an apparatus and a system that are related to the foregoing method. For the packet transmission method, a first PE receives a first BIER packet sent by a first CE, determines, based on the received first BIER packet, a first VPN to which the first CE belongs, and transmits the first BIER packet based on the first VPN.

Abstract: A first network device receives a BIER packet sent by a second network device. The BIER packet includes a data packet and a global VPN identifier, the global VPN identifier is for uniquely identifying, in a BIER domain, a VPN to which a source device of the data packet belongs, the global VPN identifier includes an identifier of the second network device and a first identifier, and the first identifier is for identifying, on the second network device, the VPN to which the source device of the data packet belongs. The first network device determines, based on the global VPN identifier, a first VPN corresponding to the global VPN identifier. The first network device sends the data packet to the destination device of the data packet corresponding to the first VPN.

Abstract: In accordance with an embodiment, a packet transmission method includes receiving, by a second provider edge (PE) through a multicast tunnel, a bit indexed explicit replication (BIER) packet sent by a first PE, wherein the BIER packet comprises a bit string, and the bit string indicates a customer edge (CE) designated to receive the BIER packet; and processing, by the second PE based on the bit string, the BIER packet.

Abstract: Embodiments of this application provide a next hop determining method. The method is applied to a BIER domain based on bit index forwarding routing, and includes: A third device obtains first BIER information of a first device, an attribute of the first device, second BIER information of a second device, and an attribute of the second device, where the first BIER information includes a bit forwarding router identifier BFR-id of an edge bit forwarding router BFR in a sub-domain, and the second BIER information includes the BFR-id of the edge BFR in the sub-domain. The third device determines, based on the first BIER information, the second BIER information, the attribute of the first device, and the attribute of the second device, a next hop to the edge BFR in the sub-domain.

Abstract: An IPv6 packet sending method, a device, and a system is provided. The method includes a first network device receives a first IPv6 packet, where the first IPv6 packet includes a packet header and an inner packet, and the packet header includes a hop limit field. The network device further determines whether a value of the hop limit field is less than or equal to a preset threshold, determines whether the inner packet is a multicast packet, and avoids forwarding the first IPv6 packet when the value of the hop limit field is less than or equal to the preset threshold and the inner packet is the multicast packet.

Abstract: This application provides a packet forwarding method, device, and system. The method includes: A first network device obtains a first packet, where the first packet includes a multicast packet; the first network device determines a next-hop destination address DA of the multicast packet based on a source address SA and a first correspondence relationship, where the SA is used to identify a multicast path corresponding to the multicast packet, and the first correspondence relationship includes the SA and a next-hop DA of the first network device on the multicast path; the first network device obtains a second packet based on the next-hop DA, where the second packet is a unicast packet obtained after IPv6 encapsulation is performed on the multicast packet; and the first network device forwards the second packet along the multicast path based on the next-hop DA.

Abstract: This application provides a P2MP tree connectivity detection method, a device, and a system. The method is applied to SR domain. The SR domain includes a P2MP tree. The P2MP tree includes a first node. The first node is a root node or an intermediate replication node of the P2MP tree. The method includes: The first node determines a first next-hop node of the first node based on replication branch information; and the first node sends a first request message to the first next-hop node. The first request message includes a segment identifier SID of the first next-hop node. The first request message includes a first identifier. The first identifier indicates that the first request message is for connectivity detection.

Abstract: This application describes a multicast packet sending method, apparatus, and system. The method includes a first multicast root node and a second multicast root node belonging to a same VRRP group. The first multicast root node receives a first multicast packet from a specified multicast source, and the second multicast root node receives a second multicast packet from the same specified multicast source, where the first multicast packet and the second multicast packet include same multicast data. The first multicast root node sends the first multicast packet to a first node based on the first multicast root node being a master root node. The second multicast root node discards the second multicast packet based on the second multicast root node being a backup root node. The method reduces waste of a network bandwidth resource.

Abstract: In a packet sending method, a first network device receives a first multicast packet, and determines first information based on the first multicast packet, where the first information indicates an attribute of the first multicast packet. The first network device determines that a state of a first link interface is unavailable, and performs a modulo operation on the first information based on a second parameter, to obtain second indication information, where the second indication information indicates a second link interface through which the first network device forwards the first multicast packet, the second parameter is a quantity of link interfaces whose states are available in a first load balancing group, and the first load balancing group includes the first link interface and the second link interface. The first network device forwards the first multicast packet through the second link interface.

Abstract: A destination node device starts a timer when the destination node device determines that a network topology changes; before the timer expires, the destination node device forwards the BIER packet by using an old forwarding table and establishes a new forwarding table, where the old forwarding table is a forwarding table used by the destination node device before the network topology changes, the new forwarding table is a forwarding table established by the destination node device based on the changed network topology; and after the timer expires, the destination node device switches the old forwarding table to the new forwarding table, and forwards the BIER packet according to the new forwarding table.

Abstract: In a VXLAN configuration method, a first network device obtains configuration information, generates first GRASP information based on the configuration information, and sends the first GRASP information to a second network device, where the configuration information includes VTEP device information, a plurality of pieces of VTEP device information are respectively used to indicate a plurality of VTEPs included in a VXLAN, the first GRASP information includes objective information, and the objective information is used to carry the configuration information. The second network device receives the first GRASP information and establishes a VXLAN tunnel based on the first GRASP information. In this way, automatic VXLAN configuration is implemented.

Abstract: In a VXLAN configuration method, a first network device obtains configuration information, generates first GRASP information based on the configuration information, and sends the first GRASP information to a second network device, where the configuration information includes VTEP device information, a plurality of pieces of VTEP device information are respectively used to indicate a plurality of VTEPs included in a VXLAN, the first GRASP information includes objective information, and the objective information is used to carry the configuration information. The second network device receives the first GRASP information and establishes a VXLAN tunnel based on the first GRASP information. In this way, automatic VXLAN configuration is implemented.