I would like to know exactly NNHOP protection in MPLS core.
first of all, Please check the attached file.
Regard the attached file. when the R4 fail, the R2 activate the FRR NNHOP protection through R3.
the most thing that I want to know is that How R2 know the label 36? the label is local siginificanly so R2 doesn't know the label 36.
when NNHOP is activated, the R2 is pushed 25/36 ? in other protocol RSVP?