binding-sid (SRv6 TE Policy view)

Usage Scenario

Each SRv6 TE Policy has a binding SID (BSID). The binding SID provides scalability, network opacity, and service independence.

After a binding SID is configured for an SRv6 TE Policy, the node where the SRv6 TE Policy is configured can function as a stitching node. Only one binding SID can be configured for each SRv6 TE Policy.

End.B6 (short for endpoint bound to an SRv6 TE Policy) is mainly used in scenarios such as traffic steering into SRv6 TE Policies, tunnel stitching, and SD-WAN route selection. End.B6 covers End.B6.Insert and End.B6.Encaps. The End.B6.Insert instruction can be disassembled into End + B6 + Insert, where B6 indicates the application of an SRv6 TE Policy and Insert indicates the insertion of an SRH after the IPv6 header. This instruction includes the following operations: inserts an SRH (including the corresponding segment list) after the IPv6 header, sets the destination address to the first SID of a specified SRv6 TE Policy, searches the routing table, and forwards the new IPv6 packet accordingly.

The End.B6.Encaps instruction can be disassembled into End + B6 + Encaps, where B6 indicates the application of an SRv6 TE Policy and Encaps indicates the encapsulation of an outer IPv6 header and SRH. This instruction includes the following operations: decrements the SL value of the inner SRH by 1, copies the SID to which the SL field is pointing to the DA field of the inner IPv6 header, encapsulates an IPv6 header and SRH (including the corresponding segment list), sets the source address to the address of the current node and the destination address to the first SID of the involved SRv6 TE Policy, sets other fields in the outer IPv6 header, searches the routing table, and forwards the new IPv6 packet accordingly.

Prerequisites

Run the srv6-te-policy locator command to associate the SRv6 TE Policy with a Locator, and then you can configure the Binding SID of the SRv6 TE Policy within the Locator.