Determining LSP Status
Display detailed information about Resource Reservation Protocol (RSVP) objects and the label-switched path (LSP) history to pinpoint a problem with the LSP.
Figure 1 illustrates the network topology used in this topic. For more details about the router configurations in this network, see Checklist for Configuring and Verifying an MPLS Network.
Figure 1: MPLS Network Topology
To determine the LSP state, follow these steps:
Check the Status of the LSP
Purpose
Display the status of the label-switched pathe (LSP).
Action
To determine the LSP status, on the ingress router, enter the following Junos OS command-line interface (CLI) operational mode command:
Sample Output
user@R1> show mpls lsp Ingress LSP: 1 sessions To From State Rt ActivePath P LSPname 10.0.0.6 10.0.0.1 Up 1 * R1-to-R6 Total 1 displayed, Up 1, Down 0 Egress LSP: 1 sessions To From State Rt Style Labelin Labelout LSPname 10.0.0.1 10.0.0.6 Up 0 1 FF 3 - R6-to-R1 Total 1 displayed, Up 1, Down 0 Transit LSP: 0 sessions Total 0 displayed, Up 0, Down 0
Meaning
The sample output is from the ingress router (R1), and shows ingress, egress, and transit LSP information. Ingress information is for the sessions that originate from this router, egress information is for sessions that terminate on this router, and transit information is for sessions that transit through this router.
There is one ingress route from R1 (10.0.0.1) to R6 (10.0.0.6). This route is currently up, and is an active route installed in the routing table (Rt). The LSP R1-to-R6 is the primary path (P) as opposed to the secondary path, and is indicated by an asterisk (*). The route to R6 does not contain a named path (ActivePath).
There is one egress LSP from R6 to R1. The State is up, with no routes installed in the routing table. RSVP reservation style (Style) consists of two parts. The first is the number of active reservations (1). The second is the reservation style, which is FF (fixed filter). The reservation style can be FF, SE (shared explicit), or WF (wildcard filter). There are three incoming labels (Labelin) and no labels going out (Labelout) for this LSP.
There are no transit LSPs.
For more information on checking the LSP state, see Checklist for Working with the Layered MPLS Troubleshooting Model.
Display Extensive Status About the LSP
Purpose
Display extensive information about LSPs, including all past state history and the reasons why an LSP might have failed.
Action
To display extensive information about LSPs, on the ingress router, enter the following Junos OS CLI operational mode command:
Sample Output
user@R1> show mpls lsp extensive
Ingress LSP: 1 sessions
10.0.0.6
From: 10.0.0.1, State: Up , ActiveRoute: 1 , LSPname: R1-to-R6
ActivePath: (primary)
LoadBalance: Random
Encoding type: Packet, Switching type: Packet, GPID: IPv4
*Primary State: Up
Computed ERO (S [L] denotes strict [loose] hops): (CSPF metric: 20)
10.1.13.2 S 10.1.36.2 S
Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt):
10.1.13.2 10.1.36.2
91 Aug 17 12:22:52 Selected as active path
90 Aug 17 12:22:52 Record Route: 10.1.13.2 10.1.36.2
89 Aug 17 12:22:52 Up
88 Aug 17 12:22:52 Originate Call
87 Aug 17 12:22:52 CSPF: computation result accepted
86 Aug 17 12:22:23 CSPF failed: no route toward 10.0.0.6[13920 times]
85 Aug 12 19:12:51 Clear Call
84 Aug 12 19:12:50 10.1.56.2: MPLS label allocation failure
83 Aug 12 19:12:47 Deselected as active
82 Aug 12 19:12:47 10.1.56.2: MPLS label allocation failure
81 Aug 12 19:12:47 ResvTear received
80 Aug 12 19:12:47 Down
79 Aug 12 19:12:31 10.1.56.2: MPLS label allocation failure[4 times]
78 Aug 12 19:09:58 Selected as active path
77 Aug 12 19:09:58 Record Route: 10.1.15.2 10.1.56.2
76 Aug 12 19:09:58 Up
75 Aug 12 19:09:57 Originate Call
74 Aug 12 19:09:57 CSPF: computation result accepted
73 Aug 12 19:09:29 CSPF failed: no route toward 10.0.0.6[11 times]
72 Aug 12 19:04:36 Clear Call
71 Aug 12 19:04:23 Deselected as active
70 Aug 12 19:04:23 ResvTear received
69 Aug 12 19:04:23 Down
68 Aug 12 19:04:23 CSPF failed: no route toward 10.0.0.6
67 Aug 12 19:04:23 10.1.15.2: Session preempted
66 Aug 12 16:45:35 Record Route: 10.1.15.2 10.1.56.2
65 Aug 12 16:45:35 Up
64 Aug 12 16:45:35 Clear Call
63 Aug 12 16:45:35 CSPF: computation result accepted
62 Aug 12 16:45:35 ResvTear received
61 Aug 12 16:45:35 Down
60 Aug 12 16:45:35 10.1.13.2: Session preempted
59 Aug 12 14:50:52 Selected as active path
58 Aug 12 14:50:52 Record Route: 10.1.13.2 10.1.36.2
57 Aug 12 14:50:52 Up
56 Aug 12 14:50:52 Originate Call
55 Aug 12 14:50:52 CSPF: computation result accepted
54 Aug 12 14:50:23 CSPF failed: no route toward 10.0.0.6[7 times]
53 Aug 12 14:47:22 Deselected as active
52 Aug 12 14:47:22 CSPF failed: no route toward 10.0.0.6
51 Aug 12 14:47:22 Clear Call
50 Aug 12 14:47:22 CSPF: link down/deleted 10.1.12.1(R1.00/10.0.0.1)->10.1.12.2(R2.00/10.0.0.2)
49 Aug 12 14:47:22 CSPF: link down/deleted 10.1.15.1(R1.00/10.0.0.1)->10.1.15.2(R5.00/10.0.0.5)
48 Aug 12 14:47:22 10.1.15.1: MPLS label allocation failure
47 Aug 12 14:47:22 Clear Call
46 Aug 12 14:47:22 CSPF: computation result accepted
45 Aug 12 14:47:22 10.1.12.1: MPLS label allocation failure
44 Aug 12 14:47:22 MPLS label allocation failure
43 Aug 12 14:47:22 Down
42 Jul 23 11:27:21 Selected as active path
Created: Sat Jul 10 18:18:44 2004
Total 1 displayed, Up 1, Down 0
Egress LSP: 1 sessions
10.0.0.1
From: 10.0.0.6, LSPstate: Up , ActiveRoute: 0
LSPname: R6-to-R1 , LSPpath: Primary
Suggested label received: -, Suggested label sent: -
Recovery label received: -, Recovery label sent: -
Resv style: 1 FF , Label in: 3 , Label out: -
Time left: 141, Since: Tue Aug 17 12:23:14 2004
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Port number: sender 1 receiver 39024 protocol 0
PATH rcvfrom: 10.1.15.2 (so-0/0/1.0) 130 pkts
Adspec: received MTU 1500
PATH sentto: localclient
RESV rcvfrom: localclient
Record route: 10.1.56.2 10.1.15.2 <self>
Total 1 displayed, Up 1, Down 0
Transit LSP: 0 sessions
Total 0 displayed, Up 0, Down 0
Meaning
The sample output is from the ingress router (R1), and shows ingress, egress, and transit LSP information in detail, including all past state history and the reasons why an LSP failed. Ingress information is for sessions that originate from this router, egress information is for sessions that terminate on this router, and transit information is for sessions that transit through this router.
There is one ingress route from R1 (10.0.0.1) to R6 (10.0.0.6). This route is currently up (State), with one route actively using the LSP, R1-to-R6. The LSP active path is the primary path. Even if the LSP does not contain a primary or secondary keyword, the router still treats the LSP as a primary LSP, indicating that if the LSP fails, the router will attempt to signal inactive LSPs at 30-second intervals, by default.
Load balancing is Random, which is the default, indicating that when selecting the physical path for an LSP, the router randomly selects among equal-cost paths that have an equal hop count. Other options that you can configure are Least-fill and Most-fill. Least-fill places the LSP over the least utilized link of the equal-cost paths with equal hop count. Most-fill places the LSP over the most utilized link of the equal-cost paths sharing an equal hop count. Utilization is based on the percentage of available bandwidth.
The Encoding type field shows Generalized MPLS (GMPLS) signaling parameters (Packet), indicating IPv4. The Switching type is Packet, and the Generalized Payload Identifier (GPID) is IPv4.
The primary path is the active path, as indicated by an asterisk (*). The state of the LSP is Up.
The Explicit Route Object (ERO) includes the Constrained Shortest Path First (CSPF) cost (20) for the physical path that the LSP follows. The presence of the CSPF metric indicates that this is a CSPF LSP. The absence of the CSPF metric indicates a no-CSPF LSP.
The field 10.1.13.2 S indicates the actual ERO. The RSVP signaling messages went to 10.1.13.2 strictly (as a next hop) and finished at 10.1.36.2 strictly. All ERO addresses are strict hops when the LSP is a CSPF LSP. Loose hops can only display in a no-CSPF LSP.
The received Record Route Object (RRO) has the following protection flags:
- 0x01—Local protection available. The link downstream of this node is protected by a local repair mechanism. This flag can only be set if the Local protection flag was set in the SESSION_ATTRIBUTE object of the corresponding path message.
- 0x02—Local protection in use. A local repair mechanism is in use to maintain this tunnel (usually because of an outage of the link it was routed over previously).
- 0x04— Bandwidth protection. The downstream router has a backup path providing the same bandwidth guarantee as the protected LSP for the protected section.
- 0x08—Node protection. The downstream router has a backup path providing protection against link and node failure on the corresponding path section. If the downstream router can set up only a link-protection backup path, the “Local protection available” bit is set but the “Node protection” bit is cleared.
- 0x10—Preemption pending. The preempting node sets this flag if a pending preemption is in progress for the traffic engineered LSP. This indicates to the ingress label edge router (LER) of this LSP that it should be rerouted.
For more information on protection flags, see the Junos Routing Protocols and Policies Command Reference.
The field 10.1.13.2.10.1.36.2 is the actual received record route (RRO). Note that the addresses in the RRO field match those in the ERO field. This is the normal case for CSPF LSPs. If the RRO and ERO addresses do not match for a CSPF LSP, the LSP has to reroute or detour.
The lines numbered 91 through 42 contain the 49 most recent entries to the history log. Each line is time stamped. The most recent entries have the largest log history number and are at the top of the log, indicating that line 91 is the most recent history log entry. When you read the log, start with the oldest entry (42) to the most recent (91).
The history log was started on July 10, and displays the following sequence of activities: an LSP was selected as active, was found to be down, MPLS label allocation failed several times, was deleted several times, was preempted because of an ResvTear, was deselected as active, and was cleared. In the end, the router computed a CSPF ERO, signaled the call, the LSP came up with the listed RRO (line 90), and was listed as active.
For more information on error messages, see the Junos MPLS Network Operations Guide Log Reference.
The total number of ingress LSPs displayed is 1, with 1 up and 0 down. The number in the Up field plus the number in the Down field should equal the total.
There is one egress LSP session from R6 to R1. The State is up, with no routes installed in the routing table. RSVP reservation style (Style) consists of two parts. The first is the number of active reservations (1). The second is the reservation style, which is FF (fixed filter). The reservation style can be FF, SE (shared explicit), or WF (wildcard filter). There are three incoming labels (Labelin) and no labels going out (Labelout) for this LSP.
There are no transit LSPs.
For more information on checking the LSP state, see Checklist for Working with the Layered MPLS Troubleshooting Model.
