How does SR policy operate in Segment Routing Traffic Engineering?

SR policies are not automatically deactivated upon learning something; their state depends on the validity of their candidate paths and administrative status.

'Invalidation drop' refers to specific handling of invalid SIDs within a candidate path, not the primary mechanism of policy forwarding entry removal. If a path becomes invalid, the policy might try another candidate path, not necessarily remove the overall forwarding entry.

Traffic steering for an SR policy typically selects one active candidate path (SID list) based on policy constraints; traffic is not inherently ECMP-steered across multiple SID lists associated with a single designated path.

When an SR policy becomes active on the headend router, it creates a forwarding entry identified by a Binding SID (BSID). This BSID-keyed entry allows the router to encapsulate and steer incoming packets that match the SR policy's criteria (e.g., destination, color) along the specific Segment List (SL) chosen as the active path for that policy.