Discussion

RSVP RRO in the path calculation log (line 4 in the log) contains the path being followed
by the primary LSP. This LSP goes first to R3 (10.1.31.2) and then to R4
(10.1.34.2) before reaching the egress at R5 (10.1.45.2). The following command
shows that RSVP has reserved the bandwidth:
aviva@R1> show rsvp interface
RSVP interface: 2 active
Active Subscr- Static Available Reserved Highwater
Interface State resv iption BW BW BW mark
so-0/0/0.0 Up 0 100% 155.52Mbps 155.52Mbps 0bps 0bps
so-0/0/2.0 Up 1 100% 155.52Mbps 105.52Mbps 50Mbps 50Mbps
For interface so-0/0/2, which connects to R3, the first router in the LSP, the output
shows that 50 Mbps have been reserved and 105.52 Mbps are still available.
Next in the configuration is to set up a secondary path. There are two commands for
this. The first command creates the secondary path in the LSP, and the second
defines the path for MPLS. This recipe uses the standby option in the secondary path
so the path is established when the primary path is set up and remains up at all
times. This means that the secondary path is always available to take over immediately
if the primary path fails. The result is that no traffic is dropped during the time
it takes for CSPF to calculate a new route and RSVP to signal a new path.
Look at the LSP again to check that the secondary path has been set up. A quick
glance shows two RSVP sessions for the R1-to-R5 LSP:
aviva@R1> show rsvp session ingress
Ingress RSVP: 2 sessions
To From State Rt Style Labelin Labelout LSPname
10.0.0.5 10.0.0.1 Up 0 1 FF - 100144 R1-to-R5
10.0.0.5 10.0.0.1 Up 0 1 FF - 100160 R1-to-R5
Total 2 displayed, Up 2, Down 0
A detailed look at the LSP shows more information about the two paths:
aviva@R1> show mpls lsp ingress extensive
Ingress LSP: 1 sessions
10.0.0.5
From: 10.0.0.1, State: Up, ActiveRoute: 0, LSPname: R1-to-R5
ActivePath: primary-path-R1-to-R5 (primary)
LoadBalance: Random
Encoding type: Packet, Switching type: Packet, GPID: IPv4
*Primary primary-path-R1-to-R5 State: Up
Bandwidth: 50Mbps
SmartOptimizeTimer: 180
Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt):
10.1.13.2 10.1.34.2 10.1.45.2
5 Oct 7 09:15:34 Selected as active path
4 Oct 7 09:15:34 Record Route: 10.1.13.2 10.1.34.2 10.1.45.2
3 Oct 7 09:15:34 Up
2 Oct 7 09:15:34 Originate Call
1 Oct 7 09:15:05 Path name undefined or disabled[3 times]
Standby secondary-path-R1-to-R5 State: Up
This is the Title of the Book, eMatter Edition
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