BIER packet sending method and apparatus

1. A method implemented by a first node in a first bit index explicit replication (BIER) domain, wherein the method comprises:

receiving, from a second node in a second BIER domain, a packet carrying a first identifier of the second BIER domain;

determining, based on the first identifier and according to a locally configured BIER packet sending policy, a BIER packet sending policy corresponding to the first identifier, wherein the BIER packet sending policy comprises path information corresponding to the first identifier, and wherein the path information identifies a path from the first node to the second node;

encapsulating the path information into a BIER packet; and

sending, based on the path information, the BIER packet to the second BIER domain.

2. The method of claim 1 , wherein the path information comprises a segment identifier (SID) of Segment Routing (SR).

3. The method of claim 1 , wherein the path information comprises an Internet Protocol (IP) of a User Datagram Protocol (UDP) tunnel.

4. The method of claim 1 , wherein the path information comprises a segment identifier (SID) of a Segment Routing over Internet Protocol version 6 (SRv6).

5. The method of claim 1 , wherein the path information comprises an Internet Protocol (IP) of a Generic Routing Encapsulation (GRE) tunnel.

6. The method of claim 1 , wherein the BIER packet sending policy further comprises a second identifier of a bit index forwarding table (BIFT-ID) corresponding to the first identifier, and wherein encapsulating the BIER packet further comprises encapsulating a BIER header of the BIER packet based on the BIFT ID.

7. The method of claim 1 , wherein the first node is a head node, and wherein the second node is a leaf node.

8. A first node in a first bit index explicit replication (BIER) domain, wherein the first node comprises:

a memory configured to store programming instructions; and

a processor coupled to the memory, wherein the programming instructions cause the processor to be configured to:

receive, from a second node in a second BIER domain, a packet carrying a first identifier of the second BIER domain;

determine, based on the first identifier and according to a locally configured BIER packet sending policy, a BIER packet sending policy corresponding to the first identifier, wherein the BIER packet sending policy comprises path information corresponding to the first identifier, and wherein the path information identifies a path from the first node to the second node;

encapsulate the path information into a BIER packet; and

send, based on the path information, the BIER packet to the second BIER domain.

9. The first node of claim 8 , wherein the path information comprises a segment identifier (SID) of Segment Routing (SR).

10. The first node of claim 8 , wherein the path information comprises an Internet Protocol (IP) of a User Datagram Protocol (UDP) tunnel.

11. The first node of claim 8 , wherein the path information comprises a segment identifier (SID) of a Segment Routing over Internet Protocol version 6 (SRv6).

12. The first node of claim 8 , wherein the path information comprises an Internet Protocol (IP) of a Generic Routing Encapsulation (GRE) tunnel.

13. The first node of claim 8 , wherein the BIER packet sending policy further comprises a second identifier of a bit index forwarding table (BIFT-ID) corresponding to the first identifier, and wherein the programming instructions further cause the processor to be configured to encapsulate a BIER header of the BIER packet based on the second identifier.

14. The first node of claim 8 , wherein the first node is a head node, and wherein the second node is a leaf node.

15. A computer program product comprising computer-executable instructions stored on a non-transitory computer-readable storage medium that, when executed by a processor of a first node in a first bit index explicit replication (BIER) domain, cause the first node to:

receive, from a second node in a second BIER domain, a packet carrying a first identifier of the second BIER domain;

determine, based on the first identifier and according to a locally configured BIER packet sending policy, a BIER packet sending policy corresponding to the first identifier, wherein the BIER packet sending policy comprises path information corresponding to the first identifier, and wherein the path information identifies a path from the first node to the second node;

encapsulate the path information into a BIER packet; and

send, based on the path information, the BIER packet to the second BIER domain.

16. The computer program product of claim 15 , wherein the BIER packet sending policy further comprises a second identifier of a bit index forwarding table (BIFT-ID) corresponding to the first identifier, and wherein the computer-executable instructions further cause the first node to encapsulate a BIER header of the BIER packet based on the BIFT-ID.

17. The computer program product of claim 15 , wherein the first node is a head node, and wherein the second node is a leaf node.

18. The computer program product of claim 15 , wherein the second BIER domain comprises a plurality of sub-domains, and wherein the first identifier is associated with each of the sub-domains.

19. The method of claim 1 , wherein the second BIER domain comprises a plurality of sub-domains, and wherein the first identifier is associated with each of the sub-domains.

20. The first node of claim 8 , wherein the second BIER domain comprises a plurality of sub-domains, and wherein the first identifier is associated with each of the sub-domains.