Route processing method and related device

Patent metadata

Field	Value
Publication number	US-12438807-B2
Application number	US-202218066625-A
Country	US
Kind code	B2
Filing date	Dec 15, 2022
Priority date	Jun 16, 2020
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

A first network device obtains first information. The first information indicates that a first link is faulty, and the first link is a link between any two network devices in a network system to which the first network device belongs. The first network device sends the first information to a second network device by using BGP, for example, sends a link fault message to the second network device by using BGP. The link fault message carries the first information. The second network device is a neighbor device of the first network device. The first network device determines an unreachable route in a routing table of the first network device based on the first information and a topology of the network system. A path corresponding to the unreachable route includes the first link. The first network device marks the unreachable route as invalid.

First claim

What is claimed is:

1. A method, comprising:
obtaining, by a first network device, first information, wherein the first information indicates that a first link is faulty, and the first link is a link between network devices in a network system to which the first network device belongs;
sending, by the first network device, the first information to a second network device, wherein the second network device is a first neighbor device of the first network device; and
after sending the first information to the second network device, determining, by the first network device, an unreachable route in a routing table of the first network device based on the first information and a topology of the network system, wherein a path corresponding to the unreachable route comprises the first link, and determining, by the first network device, the unreachable route in the routing table of the first network device based on the first information and the topology of the network system comprises:
when the first network device is not an end device of the first link, determining, by the first network device based on the first information, information about a second neighbor device of the first network device that sends the first information, and the topology of the network system, an unreachable network device of the second neighbor device that sends the first information, and determining that a route that is generated by the unreachable network device and received by the first neighbor device is the unreachable route.

2. The method according to claim 1 , further comprising:
receiving, by the first network device, second information, wherein the second information comprises an identifier of a third network device and information about a link between the third network device and a neighbor device of the third network device, and the third network device is a network device other than the first network device in the network system;
forwarding, by the first network device, the second information to the first neighbor device of the first network device or to a further neighbor device of the first network device; and
generating, by the first network device, the topology of the network system based on the second information.

3. The method according to claim 2 , wherein the identifier of the third network device comprises a loopback interface address of the third network device, and the information about the link between the third network device and the neighbor device of the third network device comprises an interface address of the third network device and an interface address of the neighbor device of the third network device.

4. The method according to claim 1 , wherein determining, by the first network device, the unreachable route in the routing table of the first network device based on the first information and the topology of the network system comprises:
when the first network device is a first end device of the first link, determining, by the first network device, that a route that comprises the first link and that is advertised by a second end device of the first link is the unreachable route.

5. The method according to claim 4 , wherein after determining, by the first network device, that the route that comprises the first link and that is advertised by the second end device of the first link is the unreachable route, the method further comprises:
sending, by the first network device, third information to the second network device, wherein the third information indicates to the second network device to withdraw the route that comprises the first link and that is advertised by the second end device of the first link.

6. The method according to claim 1 , wherein obtaining, by the first network device, the first information comprises:
obtaining, by the first network device, the first information by detecting a status of the first link or a status of an interface corresponding to the first link.

7. The method according to claim 1 , wherein obtaining, by the first network device, the first information comprises:
receiving, by the first network device, the first information from a fourth network device, wherein the fourth network device is a further neighbor device of the first network device.

8. The method according to claim 7 , further comprising:
receiving, by the first network device, fourth information from the fourth network device, wherein the fourth information indicates to the first network device to withdraw a route advertised by an end device of the first link; and
deleting, by the first network device, the unreachable route from the routing table based on the fourth information.

9. The method according to claim 1 , wherein:
sending, by the first network device, the first information to the second network device comprises:
sending, by the first network device, the first information to the second network device by using an extended border gateway protocol (BGP); and

the method further comprises:
deleting, by the first network device, the unreachable route or marking the unreachable route as invalid.

10. A network device, wherein the network device is configured to act as a first network device, and the network device comprises:
at least one processor; and
a non-transitory computer readable storage medium storing a program that is executable by the at least one processor, the program including instructions to:
obtain first information, wherein the first information indicates that a first link is faulty, and the first link is a link between network devices in a network system to which the first network device belongs;
send the first information to a second network device, wherein the second network device is a first neighbor device of the first network device;
after sending the first information to the second network device, determine an unreachable route in a routing table of the first network device based on the first information and a topology of the network system, wherein a path corresponding to the unreachable route comprises the first link; and
when the first network device is not an end device of the first link, determine, based on the first information, information about a second neighbor device of the first network device that sends the first information, and the topology of the network system, an unreachable network device of the second neighbor device, and determine that a route that is generated by the unreachable network device and received by the first neighbor device is the unreachable route.

11. The network device according to claim 10 , wherein the program further includes instructions to:
receive second information, wherein the second information comprises an identifier of a third network device and information about a link between the third network device and a neighbor device of the third network device, and the third network device is a network device other than the first network device in the network system;
forward the second information to the second network device by using a border gateway protocol (BGP); and
generate the topology of the network system based on the second information.

12. The network device according to claim 11 , wherein the identifier of the third network device comprises a loopback interface address of the third network device, and the information about the link between the third network device and the neighbor device of the third network device comprises an interface address of the third network device and an interface address of the neighbor device of the third network device.

13. The network device according to claim 10 , wherein the program further includes instructions to:
when the first

Assignees

• Huawei Tech Co Ltd

Inventors

• Hao Weiguo
• Wang Haibo
• He Xingjian
• Yan Gang
• Gao Liangchuan

Classifications

• H04L45/02

  Topology update or discovery · CPC title

• H04L45/033

  by updating distance vector protocols · CPC title

• H04L45/28 Primary

  using route fault recovery · CPC title