BIER packet forwarding method, device, and system

A method, comprising:

• determining, by a second network device, a correspondence between a global virtual private network (VPN) identifier and a second route target attribute, wherein the global VPN identifier uniquely identifies, in a bit indexed explicit replication (BIER) domain, a VPN to which a source device of a data packet belongs, the global VPN identifier comprises an identifier of the second network device and a first identifier, the identifier of the second network device identifies the second network device in the BIER domain, the first identifier identifies, on the second network device, the VPN to which the source device of the data packet belongs, and the second network device is an ingress node of the BIER domain;
• sending, by the second network device, a control packet to a first network device, wherein the control packet comprises the global VPN identifier and the second route target attribute, and the first network device is an egress node of the BIER domain;
• obtaining, by the second network device, the data packet, wherein the VPN to which the source device of the data packet belongs corresponds to the second route target attribute;
• obtaining, by the second network device, a BIER packet based on the correspondence, wherein the BIER packet comprises the data packet and the global VPN identifier;
• and
• sending, by the second network device, the BIER packet to the first network device;
• and
• wherein the identifier of the second network device comprises any one of the following:
• an internet protocol version 4 (IPv4) address of the second network device, an internet protocol version 6 (IPv6) address of the second network device, a prefix of the IPv6 address of the second network device, or a media access control (MAC) address of the second network device.

A first network device, comprising:

• a non-transitory memory storing instructions;
• and
• at least one processor coupled to the non-transitory memory, wherein the instructions, when executed by the at least one processor, cause the first network device to be configured to:
• receive a bit indexed explicit replication (BIER) packet sent by a second network device, wherein the BIER packet comprises a data packet and a global virtual private network (VPN) identifier, the global VPN identifier uniquely identifies, in a BIER domain, a VPN to which a source device of the data packet belongs, the global VPN identifier comprises an identifier of the second network device and a first identifier, the identifier of the second network device identifies the second network device in the BIER domain, the first identifier identifies, on the second network device, the VPN to which the source device of the data packet belongs, the second network device is an ingress node of the BIER domain, and the first network device is an egress node of the BIER domain;
• determine, based on the global VPN identifier, a first VPN corresponding to the global VPN identifier, wherein the first VPN is a VPN that is determined by the first network device to which a destination device of the data packet belongs;
• and
• send the data packet to the destination device of the data packet corresponding to the first VPN;
• and
• wherein the identifier of the second network device comprises any one of the following:
• an internet protocol version 4 (IPv4) address of the second network device, an internet protocol version 6 (IPv6) address of the second network device, a prefix of the IPv6 address of the second network device, or a media access control (MAC) address of the second network device.

A second network device, comprising:

• a non-transitory memory storing instructions;
• and
• at least one processor coupled to the non-transitory memory;
• wherein the instructions, when executed by the at least one processor, cause the second network device to be configured to:
• determine a correspondence between a global virtual private network (VPN) identifier and a second route target attribute, wherein the global VPN identifier uniquely identifies, in a bit indexed explicit replication (BIER) domain, a VPN to which a source device of a data packet belongs, the global VPN identifier comprises an identifier of the second network device and a first identifier, the identifier of the second network device identifies the second network device in the BIER domain, the first identifier identifies, on the second network device, the VPN to which the source device of the data packet belongs, and the second network device is an ingress node of the BIER domain;
• send a control packet to a first network device, wherein the control packet comprises the global VPN identifier and the second route target attribute, and the first network device is an egress node of the BIER domain;
• and
• obtain the data packet, wherein the VPN to which the source device of the data packet belongs corresponds to the second route target attribute, wherein
• obtain a BIER packet based on the correspondence, wherein the BIER packet comprises the data packet and the global VPN identifier;
• and
• send the BIER packet to the first network device;
• and
• wherein the identifier of the second network device comprises any one of the following:
• an internet protocol version 4 (IPv4) address of the second network device, an internet protocol version 6 (IPv6) address of the second network device, a prefix of the IPv6 address of the second network device, or a media access control (MAC) address of the second network device.