Abstract: In a packet processing method, when sending an SR policy to a headend of the SR policy, a control entity notifies the headend of a usage of the SR policy based on indication information of the SR policy. After sensing the usage of the SR policy based on the received indication information, the headend may perform corresponding operations based on different usages, to ensure that the SR policy takes effect. For example, when it is ensured that a quantity of SIDs included in a segment list in an end-to-end SR policy exceeds an MSD of a network device, an associated SR policy corresponding to the end-to-end SR policy can be effectively deployed, and a service packet can be effectively forwarded based on the end-to-end SR policy and the associated SR policy.

Abstract: This application discloses a packet processing method including: receiving a first packet that includes a DA field and an SRH, where the DA field includes at least one C-SID that is sequentially arranged; determining, depending on whether another C-SID is further included after a first C-SID corresponding to the first node in the at least one C-SID, whether a first processing flavor corresponding to the first C-SID indicates a movement operation or a replacement operation; and if the first processing flavor indicates a movement operation, moving a target field that is after the first C-SID and that is in the DA field, to enable the target field to cover the first C-SID in the DA field; or if the first processing flavor indicates a replacement operation, replacing the first C-SID in the DA field with a second C-SID in the SRH.

Abstract: This application provides a packet processing method and a related device. An SR policy on a network device includes a segment list, endpoint information, and indication information, and the indication information indicates whether the segment list points to an endpoint indicated by the endpoint information in the SR policy. When receiving a service packet whose destination address matches the SR policy, the network device determines, based on the indication information in the SR policy, whether the segment list points to the endpoint of the SR policy, encapsulates the service packet based on a determining result, and forwards an encapsulated service packet according to an SR path determined based on the segment list.

Abstract: This application provides a transmission path determining method and apparatus. The method includes: A first network device obtains an SR policy, where the SR policy includes active path information and backup path information. The active path information includes a first update threshold and at least one first segment list, the first segment list indicates an SR path for traffic from the first network device to a second network device, and the first update threshold indicates a threshold used to update an SR path from the first network device to the second network device. When transmitting the traffic through a path indicated by the active path information, the first network device determines, based on the first update threshold and transmission performance of an SR path indicated by each first segment list, whether quality of service of the current transmission path meets an expectation.

Abstract: A binding segment identifier processing method and a device are provided. The method includes a network device receives a message sent by a controller, where the message includes type information and a segment identifier, and the type information indicates that the segment identifier is a binding segment identifier BSID. The network device performs a processing action on the BSID based on the type information. According to embodiments of this application, the network device can identify the BSID, to resolve a technical problem that an incorrect processing result is caused when a segment identifier list of the network device includes the BSID.

Abstract: This application discloses a route selection method and a related device. A control entity determines first metric information of a first segment routing (SR) path, generates a first border gateway protocol (BGP) update message including the first metric information, and sends the first BGP update message to an ingress node of the first SR path, where the first metric information represents quality of the first SR path, the first metric information is used for route selection on a plurality of paths, each of the plurality of paths has a same IP prefix of a destination node, and the plurality of paths include the first SR path. According to the method, the control entity can send, to the ingress node of the SR path by using the BGP update message, the metric information that represents the quality of the SR path.

Abstract: Embodiments of this application provide a communication method and apparatus, so that packets of different services can be sent, based on an SR technology, on a same path specified by an SR policy. This avoids a problem that a great limitation exists in an implementation of dual-stack reconstruction, and improves communication efficiency. In the method, after receiving a first packet, a first network device forwards the first packet to a second network device based on a path specified by an SR policy. A destination endpoint specified by the SR policy is the second network device. An identifier of the destination endpoint includes a first IP address of the second network device and a second IP address of the second network device.

Abstract: A packet forwarding method implemented by a head node, includes receiving a first packet and a second packet, where the first packet is a packet forwarded by using a first network slice, and the second packet is a packet forwarded by using a second network slice; in response to the first packet matching a first segment routing policy, generating a third packet based on the first packet, where the third packet carries slice information of the first network slice and a first SID list; in response to the second packet matching the first segment routing policy, generating a fourth packet based on the second packet, where the fourth packet carries slice information of the second network slice and the first SID list; and forwarding the third packet and the fourth packet.

Abstract: A obtaining method and apparatus, a device, and a storage medium, and pertains to the field of communication technologies. The method includes: a first node obtains first measurement information and second measurement information, where the first measurement information is measurement information of a first SR path, the second measurement information is measurement information of a second SR path, the first SR path is an SR path from the first node to a second node, and the second SR path is an SR path from the second node to the first node; determines a bidirectional path detection result based on the first measurement information and the second measurement information; and sends a notification message to a controller, where the notification message carries the bidirectional path detection result.

Abstract: A method for obtaining path association information, a device, and a system are provided, and belong to the field of network technologies. A first network device generates a packet carrying template indication information, and sends the packet to a second network device. After receiving the packet, the second network device determines, based on the template indication information carried in the packet, a target template associated with a target forwarding path, and performs, based on the target template, an operation associated with the target forwarding path. In this way, the first network device may include template indication information corresponding to different templates in a packet, to indicate different receiving network devices to determine a target template associated with a target forwarding path, and determine, based on the target template, association information such as a path attribute or a path constraint associated with the target forwarding path.

Abstract: This application provides a method for forwarding a service packet, a method for sending an SR policy, a device, and a system, and belongs to the field of network technologies. In the solution provided in this application, a network device may forward, according to a first candidate path in an SR policy through a sub-interface corresponding to a first network slice, a service packet, and the first candidate path and a first identifier of a first network slice corresponding to the first candidate path are encapsulated in the service packet.

Abstract: A first network device obtains a first route, where the first route includes a first route prefix. The first network device advertises a second route, where the second route includes a subnet prefix and a path identifier, and a range of the subnet prefix includes a range of the first route prefix.

Abstract: A first network device obtains a subnet prefix, where the subnet prefix is a destination identifier of a traffic engineering tunnel. The first network device performs data processing based on the subnet prefix.

Abstract: A binding segment identifier processing method and a device are provided. The method includes a network device receives a message sent by a controller, where the message includes type information and a segment identifier, and the type information indicates that the segment identifier is a binding segment identifier BSID. The network device performs a processing action on the BSID based on the type information. According to embodiments of this application, the network device can identify the BSID, to resolve a technical problem that an incorrect processing result is caused when a segment identifier list of the network device includes the BSID.