RSVP-TE SRLG hold-down for CSPF path selection

Shared Risk Link Group (SRLG) hold-down mechanism allows Constrained Shortest Path First (CSPF) to avoid recently unstable network resources when computing RSVP-TE label-switched paths (LSPs). When a link associated with an SRLG experiences a link-down event, the SRLG enters a hold-down state for a configurable period. During this period, CSPF treats links belonging to that SRLG as undesirable by either penalizing links by adding a configurable SRLG cost to the traffic engineering (TE) metric or excluding those links from CSPF path computation. You can configure SRLG hold-down policy at the global level under the [edit protocols mpls srlg-hold-down] hierarchy level or for individual SRLG under the [edit routing-options srlg srlg-name] hierarchy level.