In the penultimate LSR there are following two entries for label 301040
:
root@r2> show route table mpls.0 protocol rsvp
mpls.0: 14 destinations, 14 routes (14 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
301040 *[RSVP/7/1] 00:06:53, metric 1
> to 172.22.201.14 via ge-0/0/2.0, label-switched-path r1->r4
301040(S=0) *[RSVP/7/1] 00:06:53, metric 1
> to 172.22.201.14 via ge-0/0/2.0, label-switched-path r1->r4
root@r2>
Am I correct, that one should look the S=0
as a condition, i.e if the S=0
(bottom of stack bit in MPLS header is not set) then do something and this something can be different when the S=1
(bottom of stack bit in MPLS header is set)? For example, LSR could swap the label 301040
with label 12345
if it is at the bottom of the stack or pop the label 301040
if it is not at the bottom of the stack.