Displaying Autobandwidth Events
Purpose
Automatic autobandwidth allocation allows an MPLS tunnel to automatically adjust its bandwidth allocation based on the volume of traffic flowing through the tunnel. Bandwidth allocation is adjusted according to a specified time interval when current maximum average bandwidth usage is compared with the allocated bandwidth for the LSP. If the bandwidth needs adjustment, a path with the new adjusted bandwidth is computed. The LSP's traffic is routed through the new path and the old path is removed.
Manual autobandwidth adjustment is used on the active LSP path when you do not wish to wait for the specified time interval to trigger an autobandwidth adjustment. The minimum specified time interval is 5 minutes (300 seconds) for MPLS LSP automatic bandwidth allocation adjustment. For more information on configuring autobandwidth, see the JUNOS MPLS Applications Configuration Guide.
Autobandwidth success and failure is logged in the output of the show mpls lsp extensive command. Figure 1 illustrates the example MPLS network used in this chapter to demonstrate autobandwidth LSP events.
The MPLS network in Figure 1 illustrates a router-only network with SONET interfaces that consists of the following components:
- A full-mesh interior BGP (IBGP) topology, using AS 65432.
- MPLS is enabled on all routers.
- Autobandwidth is configured on ingress router
R1. - To produce the autobandwidth events, Resource Reservation Protocol (RSVP) is disabled on interfaces that could provide an alternate route for the LSP.
- A policy is configured on ingress router
R1that advertises new routes into the network. - An LSP is established between routers
R1andR3,R1-to-R3. - An LSP is established between router
R1andR6,R1-to-R6.
The network shown in Figure 1 is a BGP full-mesh network. Since route reflectors and confederations are not used to propagate BGP learned routes, each router must have a BGP session with every other router running BGP.
Action
To display autobandwidth events, enter the following JUNOS command-line interface (CLI) operational mode command from the ingress router:
user@host> show mpls lsp extensive
Sample Output 1
user@R1# run show mpls lsp extensive
Ingress LSP: 3 sessions
10.0.0.3
From: 10.0.0.1, State: Up, ActiveRoute: 5, LSPname: R1-to-R3
ActivePath: (primary)
LoadBalance: Random
Metric: 1
Autobandwidth
MinBW: 155Mbps MaxBW: 155Mbps
AdjustTimer: 300 secs AdjustThreshold: 10%
Max AvgBW util: 392bps, Bandwidth Adjustment in 101 second(s).
Encoding type: Packet, Switching type: Packet, GPID: IPv4
*Primary State: Up
Bandwidth: 140Mbps
Computed ERO (S [L] denotes strict [loose] hops): (CSPF metric: 10)
10.1.13.2 S
Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt):
10.1.13.2
13 Feb 17 21:23:51 Manual Autobw adjustment failed
12 Feb 17 21:23:51 CSPF failed: no route toward 10.0.0.3
11 Feb 17 21:16:06 Record Route: 10.1.13.2
10 Feb 17 21:16:06 Up
9 Feb 17 21:16:06 Manual Autobw adjustment succeeded
8 Feb 17 21:16:06 Originate make-before-break call
7 Feb 17 21:16:06 CSPF: computation result accepted
6 Feb 17 21:14:51 Selected as active path
5 Feb 17 21:14:51 Record Route: 10.1.13.2
4 Feb 17 21:14:51 Up
3 Feb 17 21:14:51 Originate Call
2 Feb 17 21:14:51 CSPF: computation result accepted
1 Feb 17 21:14:22 CSPF failed: no route toward 10.0.0.3[4 times]
[...Output truncated...]
Sample Output 2
user@R1> show configuration protocols mpls
statistics {
file auto-bw.log;
interval 5;
auto-bandwidth;
}
label-switched-path R1-to-R6 {
to 10.0.0.6;
auto-bandwidth {
adjust-interval 300;
adjust-threshold 10;
minimum-bandwidth 5m;
maximum-bandwidth 80m;
}
}
label-switched-path R1-to-R3 {
to 10.0.0.3;
auto-bandwidth {
adjust-interval 300;
adjust-threshold 10;
minimum-bandwidth 155m;
maximum-bandwidth 155m;
}
}
What It Means
Sample Output 1 from ingress router R1 shows extensive ingress LSP information, including LSP events that led to an LSP failure, with the most recent events at the top.
The autobandwidth LSP events in bold are described in this chapter. Descriptions include sample output of the LSP event, an explanation of what the event means, the possible cause of the event, and any specific actions that you can take.
For completeness, autobandwidth events not included in this example output are also described in this chapter.
Sample Output 2 shows the configuration of autobandwidth on ingress router R1. LSP R1-to-R3 is configured with 155 MB of bandwidth, and LSP R1-to-R6 is configured with 5 MB of bandwidth. The autobandwidth failure events described in this chapter are created as follows: