When there is a failure on some transit router along the path of an LSP requesting detour or fast-reroute protection, the ingress router may unexpectedly tear down the detour.

This causes traffic loss for traffic using the LSP. Ingress router will subsequently re-establish the LSP along an available path to restore the LSP.

* LSP head-end router running any of the Junos and Junos Evolved platforms

* LSP configured with detour or fast-reroute protection

* A failure occurs along the primary path of the LSP that also changes IGP metric from the ingress router to the egress router

When there is a failure on some transit LSR along the path of an LSP requesting detour protection, it is possible that the metric to the LSP destination changes.

If that occurs, then the ingress router modifies the metric of the inet.3 RSVP route.

When doing this, there may be cases when the ingress router sends PathTear along the detour when the detour is locally brought down only to modify the route.

This was introduced with the fix of PR1694777 & resolved via PR1914632.