Path calculation method, apparatus, and device

1. A method comprising:

obtaining an algorithm constraint supported by each of a plurality of network devices, wherein the algorithm constraint is a constraint of a forwarding path algorithm, wherein the algorithm constraint comprises a flexible algorithm (Flex Algo);

performing network topology division on the plurality of network devices to form a network topology, wherein network devices in a same network topology support a same Flex Algo, wherein each network device in the network topology has a sub-interface corresponding to the same Flex Algo; and

calculating a forwarding path between network devices in one network topology based on the same Flex Algo supported by the network devices in the one network topology.

2. The method according to claim 1 , wherein the method further comprises:

receiving a request message for establishing a packet path from an ingress node, wherein the request message comprises a flow identifier of a packet;

determining, based on the flow identifier, the network topology for forwarding the packet using a forwarding path of the network topology;

generating a label stack corresponding to the forwarding path, wherein the label stack comprises an adjacency segment identifier and/or a node segment identifier of a network device on the forwarding path; and

sending the label stack to the ingress node.

3. The method according to claim 1 , wherein the algorithm constraint comprises an identifier of the Flex Algo and/or a link attribute comprised in the forwarding path algorithm.

4. The method according to claim 1 , wherein the method further comprises:

establishing, a first mapping relationship for each sub-interface corresponding to the same Flex Algo, wherein the first mapping relationship comprises a sub-interface information and the same Flex Algo or a sub-interface information and a color corresponding to the same Flex Algo; and

sending, to the plurality of network devices, the first mapping relationship, wherein the first mapping relationship is used by the corresponding network device to forward a packet.

5. The method according to claim 1 , wherein the sub-interface has a color as link attribute, and the Flex Algo has the color as a constraint.

6. A method applied to a first network device, comprising:

obtaining a first algorithm constraint supported by the first network device, wherein the first algorithm constraint is a constraint of a forwarding path algorithm, wherein the first algorithm constraint comprises a flexible algorithm (Flex Ago);

determining a second network device supporting a same Flex Algo as the Flex Algo supported by the first network device, and determining that the first network device and the second network device that support the same Flex Algo belong to one network topology, wherein the first network device has a first sub-interface corresponding to the Flex Algo, the second network device has a second sub-interface corresponding to the Flex Algo, wherein the first sub-interface and the second sub-interface belong to the network topology; and

calculating a first forwarding path from the first network device to the second network device in the one network topology based on the Flex Algo supported by the first network device and the second network device, wherein the first forwarding path comprises the first network device and the second network device.

7. The method according to claim 6 , wherein the first algorithm constraint comprises an identifier of the forwarding path algorithm and/or a link attribute comprised in the forwarding path algorithm.

8. The method according to claim 6 , wherein the method further comprises:

obtaining a forwarding entry for the first network device, wherein the forwarding entry comprises a segment identifier (SID) and the first sub-interface;

obtaining a packet, determining the forwarding entry based on the packet; and

forwarding the packet by the first sub-interface in the forwarding entry.

9. The method according to claim 6 , wherein the first sub-interface has a color as link attribute, the second sub-interface has the color as link attribute, and the Flex Algo has the color as a constraint.

10. An apparatus comprising:

a non-transitory memory storage comprising instructions; and

one or more processors in communication with the memory storage, wherein the instructions, when executed by the one or more processors, cause the apparatus to:

obtain an algorithm constraint supported by each of a plurality of network devices, wherein the algorithm constraint is a constraint of a forwarding path algorithm, wherein the algorithm constraint comprises a flexible algorithm (Flex Algo);

perform network topology division on the plurality of network devices to form network topology, wherein network devices in a same network topology support a same Flex Algo, wherein each network device in the network topology has a sub-interface corresponding to the same Flex Algo; and

calculate a forwarding path between network devices in one network topology based on the same Flex Algo.

11. The apparatus according to claim 10 , wherein the algorithm constraint comprises an identifier of the forwarding path algorithm and/or a link attribute comprised in the forwarding path algorithm.

12. The apparatus according to claim 10 , wherein the instructions, when executed by the one or more processors, cause the apparatus further to:

establish, a first mapping relationship for each sub-interface corresponding to the same Flex Algo, wherein the first mapping relationship comprises a sub-interface information and the same Flex Algo or a sub-interface information and a color corresponding to the same Flex Algo; and

send, to the plurality of network devices, the first mapping relationship, wherein the first mapping relationship is used by the corresponding network device to forward a packet.

13. The apparatus according to claim 10 , wherein the sub-interface has a color as link attribute, and the Flex Algo has the color as a constraint.

14. An apparatus, wherein the apparatus is applied to a first network device, and the apparatus comprises:

a non-transitory memory storage comprising instructions; and

one or more processors in communication with the memory storage, wherein the instructions, when executed by the one or more processors, cause the apparatus to:

obtain a first algorithm constraint supported by the first network device, wherein the first algorithm constraint is a constraint of a forwarding path algorithm, wherein the first algorithm constraint comprises a flexible algorithm (Flex Algo);

determine a second network device supporting a same FlexAlgo as the Flex Algo supported by the first network device, and determine that the first network device and the second network device that support the same Flex Algo are in one network topology, wherein the first network device has a first sub-interface corresponding to the Flex Algo, the second network device has a second sub-interface corresponding to the Flex Algo, wherein the first sub-interfaces and the second sub-interfaces belong to the network topology; and

calculate a first forwarding path from the first network device to the second network device in the one network topology based on the Flex Algo supported by the first network device and the second network device, wherein the first forwarding path comprises the first network device and the second network device.

15. The apparatus according to claim 14 , wherein first the algorithm constraint comprises an identifier of the Flex Algo and/or a link attribute comprised in the forwarding path algorithm.

16. The apparatus according to claim 14 , wherein the instructions, when executed by the one or more processors, cause the apparatus further to:

obtain a forwarding entry for the first network device, wherein the forwarding entry comprises a segment identifier (SID) and the first sub-interface;

obtain a packet, determining the forwarding entry based on the packet; and

forward the packet by the first sub-interface in the forwarding entry.

17. The apparatus according to claim 14 , wherein the first sub-interface has a color as link attribute, the second sub-interface has the color as link attribute, and the Flex Algo has the color as a constraint.