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Note: It is not necessary to issue the fast-reroute statement on the transit or egress routers. |
The following sections describe the steps you must take to configure and verify one-to-one backup.
The following steps show the commands you must issue to configure a LSP with fast reroute and a primary path. The show command output includes bandwidth and hop limit for your information only. Bandwidth and hop limit are not configured on R1. You can configure bandwidth and hop limit using the bandwidth and hop-limit statements at the [edit protocols mpls lsp lsp-path-name] hierarchy level.
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Note: It is not necessary to issue the fast-reroute statement on the transit or egress routers. |
Action
To configure one-to-one backup on the ingress router, follow these steps:
For example:
For example:
For example:
For example:
Sample Output
[edit protocols mpls]
user@R1# show
label-switched-path r1-to-r5 {
to 192.168.5.1;
fast-reroute;
primary via-r2;
bandwidth bps; # Bandwidth for the LSP
hop-limit number; # Maximum number of routers the LSP can traverse
}
path via-r2 {
10.0.12.14 loose;
}
[...Output truncated...]
[edit protocols mpls]
user@R1# commit
commit complete
Meaning
When the fast-reroute statement is configured, the ingress router signals all downstream routers to compute and preestablish a detour path for the LSP, using the Constrained Shortest Path First (CSPF) algorithm on the information in the local router’s traffic engineering database (TED). By default, when the detour path is calculated by CSPF, the detour path inherits the same administrative group constraints (link coloring or resource classes) as the main LSP.
You can verify that one-to-one backup is established by examining the ingress router and the other routers in the network.
To verify one-to-one backup, enter the following JUNOS CLI operational mode commands:
The following sample output is from the ingress router R1 in the network shown in Figure 5:
user@R1> show mpls lsp ingress extensive
Ingress LSP: 1 sessions
192.168.5.1
From: 192.168.1.1, State: Up, ActiveRoute: 0, LSPname: r1-to-r5
ActivePath: via-r2 (primary)
FastReroute desired
LoadBalance: Random
Encoding type: Packet, Switching type: Packet, GPID: IPv4
*Primary via-r2 State: Up
SmartOptimizeTimer: 180
Computed ERO (S [L] denotes strict [loose] hops): (CSPF metric: 3)
10.0.12.14 S 10.0.24.2 S 10.0.45.2 S
Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt):
10.0.12.14(flag=9) 10.0.24.2(flag=1) 10.0.45.2
8 May 11 14:51:46 Fast-reroute Detour Up
7 May 11 14:50:55 Record Route: 10.0.12.14(flag=9) 10.0.24.2(flag=1) 10.0.45.2
6 May 11 14:50:55 Record Route: 10.0.12.14(flag=9) 10.0.24.2 10.0.45.2
5 May 11 14:50:52 Selected as active path
4 May 11 14:50:52 Record Route: 10.0.12.14 10.0.24.2 10.0.45.2
3 May 11 14:50:52 Up
2 May 11 14:50:52 Originate Call
1 May 11 14:50:52 CSPF: computation result accepted
Created: Thu May 11 14:50:52 2006
Total 1 displayed, Up 1, Down 0
The sample output from R1 shows that the FastReroute desired object was included in the Path messages for the LSP, allowing R1 to select the active path for the LSP and establish a detour path to avoid R2.
In line 8, Fast-reroute Detour Up shows that the detour is operational. Lines 6 and 7 indicate that transit routers R2 and R4 have established their detour paths.
R2, 10.0.12.14, includes (flag=9), indicating that node protection is available for the downstream node and link. R4, 10.0.24.2, includes (flag=1), indicating that link protection is available for the next downstream link. In this case, R4 can protect only the downstream link because the node is the egress router R5, which cannot be protected. For more information about flags, see the JUNOS Feature Guide.
The output for the show mpls lsp extensive command does not show the actual path of the detour. To see the actual links used by the detour paths, you must use the show rsvp session ingress detail command.
Sample Output
The following sample output is from the ingress router R1 in the network shown in Figure 5.
user@R1> show rsvp session ingress detail
Ingress RSVP: 1 sessions
192.168.5.1
From: 192.168.1.1, LSPstate: Up, ActiveRoute: 0
LSPname: r1-to-r5, LSPpath: Primary
Suggested label received: -, Suggested label sent: -
Recovery label received: -, Recovery label sent: 100848
Resv style: 1 FF, Label in: -, Label out: 100848
Time left: -, Since: Thu May 11 14:17:15 2006
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Port number: sender 1 receiver 9228 protocol 0
FastReroute desired
PATH rcvfrom: localclient
Adspec: sent MTU 1500
Path MTU: received 1500
PATH sentto: 10.0.12.14 (fe-0/1/0.0) 35 pkts
RESV rcvfrom: 10.0.12.14 (fe-0/1/0.0) 25 pkts
Explct route: 10.0.12.14 10.0.24.2 10.0.45.2
Record route: <self> 10.0.12.14 10.0.24.2 10.0.45.2
Detour is Up
Detour Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Detour adspec: sent MTU 1500
Path MTU: received 1500
Detour PATH sentto: 10.0.17.14 (fe-0/1/1.0) 23 pkts
Detour RESV rcvfrom: 10.0.17.14 (fe-0/1/1.0) 20 pkts
Detour Explct route: 10.0.17.14 10.0.79.2 10.0.59.1
Detour Record route: <self> 10.0.17.14 10.0.79.2 10.0.59.1
Detour Label out: 100848
Total 1 displayed, Up 1, Down 0
Meaning
The sample output from R1 shows the RSVP session of the main LSP. The detour path is established, Detour is Up. The physical path of the detour is displayed in Detour Explct route. The detour path uses R7 and R9 as transit routers to reach R5, the egress router.
Sample Output
The following sample output is from the first transit router R2 in the network shown in Figure 5:
user@R2> show rsvp session transit detail
Transit RSVP: 1 sessions
192.168.5.1
From: 192.168.1.1, LSPstate: Up, ActiveRoute: 1
LSPname: r1-to-r5, LSPpath: Primary
Suggested label received: -, Suggested label sent: -
Recovery label received: -, Recovery label sent: 100448
Resv style: 1 FF, Label in: 100720, Label out: 100448
Time left: 126, Since: Wed May 10 16:12:21 2006
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Port number: sender 5 receiver 9216 protocol 0
FastReroute desired
PATH rcvfrom: 10.0.12.13 (fe-0/1/0.0) 173 pkts
Adspec: received MTU 1500 sent MTU 1500
PATH sentto: 10.0.24.2 (so-0/0/1.0) 171 pkts
RESV rcvfrom: 10.0.24.2 (so-0/0/1.0) 169 pkts
Explct route: 10.0.24.2 10.0.45.2
Record route: 10.0.12.13 <self> 10.0.24.2 10.0.45.2
Detour is Up
Detour Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Detour adspec: received MTU 1500 sent MTU 1500
Path MTU: received 1500
Detour PATH sentto: 10.0.27.2 (so-0/0/3.0) 169 pkts
Detour RESV rcvfrom: 10.0.27.2 (so-0/0/3.0) 167 pkts
Detour Explct route: 10.0.27.2 10.0.79.2 10.0.59.1
Detour Record route: 10.0.12.13 <self> 10.0.27.2 10.0.79.2 10.0.59.1
Detour Label out: 100736
Total 1 displayed, Up 1, Down 0
Meaning
The sample output from R2 shows the detour is established (Detour is Up) and avoids R4, and the link connecting R4 and R5 (10.0.45.2). The detour path is through R7 (10.0.27.2) and R9 (10.0.79.2) to R5 (10.0.59.1), which is different from the explicit route for the detour from R1. R1 has the detour passing through the 10.0.17.14 link on R7, while R1 is using the 10.0.27.2 link. Both detours merge at R9 through the 10.0.79.2 link to R5 (10.0.59.1).
Sample Output
The following sample output is from the second transit router R4 in the network shown in Figure 5:
user@R4> show rsvp session transit detail
Transit RSVP: 1 sessions
192.168.5.1
From: 192.168.1.1, LSPstate: Up, ActiveRoute: 1
LSPname: r1-to-r5, LSPpath: Primary
Suggested label received: -, Suggested label sent: -
Recovery label received: -, Recovery label sent: 3
Resv style: 1 FF, Label in: 100448, Label out: 3
Time left: 155, Since: Wed May 10 16:15:38 2006
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Port number: sender 5 receiver 9216 protocol 0
FastReroute desired
PATH rcvfrom: 10.0.24.1 (so-0/0/1.0) 178 pkts
Adspec: received MTU 1500 sent MTU 1500
PATH sentto: 10.0.45.2 (so-0/0/2.0) 178 pkts
RESV rcvfrom: 10.0.45.2 (so-0/0/2.0) 175 pkts
Explct route: 10.0.45.2
Record route: 10.0.12.13 10.0.24.1 <self> 10.0.45.2
Detour is Up
Detour Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Detour adspec: received MTU 1500 sent MTU 1500
Path MTU: received 1500
Detour PATH sentto: 10.0.49.2 (so-0/0/3.0) 176 pkts
Detour RESV rcvfrom: 10.0.49.2 (so-0/0/3.0) 175 pkts
Detour Explct route: 10.0.49.2 10.0.59.1
Detour Record route: 10.0.12.13 10.0.24.1 <self> 10.0.49.2 10.0.59.1
Detour Label out: 100352
Total 1 displayed, Up 1, Down 0
Meaning
The sample output from R4 shows the detour is established (Detour is Up) and avoids the link connecting R4 and R5 (10.0.45.2). The detour path is through R9 (10.0.49.2) to R5 (10.0.59.1). Some of the information is similar to that found in the output for R1 and R2. However, the explicit route for the detour is different, going through the link connecting R4 and R9 (so-0/0/3 or 10.0.49.2.
Sample Output
The following sample output is from R7, which is used in the detour path in the network shown in Figure 5:
user@R7> show rsvp session transit detail
Transit RSVP: 1 sessions, 1 detours
192.168.5.1
From: 192.168.1.1, LSPstate: Up, ActiveRoute: 1
LSPname: r1-to-r5, LSPpath: Primary
Suggested label received: -, Suggested label sent: -
Recovery label received: -, Recovery label sent: 100368
Resv style: 1 FF, Label in: 100736, Label out: 100368
Time left: 135, Since: Wed May 10 16:14:42 2006
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Port number: sender 5 receiver 9216 protocol 0
Detour branch from 10.0.27.1, to skip 192.168.4.1, Up
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Adspec: received MTU 1500
Path MTU: received 0
PATH rcvfrom: 10.0.27.1 (so-0/0/3.0) 179 pkts
Adspec: received MTU 1500 sent MTU 1500
PATH sentto: 10.0.79.2 (so-0/0/1.0) 177 pkts
RESV rcvfrom: 10.0.79.2 (so-0/0/1.0) 179 pkts
Explct route: 10.0.79.2 10.0.59.1
Record route: 10.0.12.13 10.0.27.1 <self> 10.0.79.2 10.0.59.1
Label in: 100736, Label out: 100368
Detour branch from 10.0.17.13, to skip 192.168.2.1, Up
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Adspec: received MTU 1500
Path MTU: received 0
PATH rcvfrom: 10.0.17.13 (fe-0/1/1.0) 179 pkts
Adspec: received MTU 1500
PATH sentto: 10.0.79.2 (so-0/0/1.0) 0 pkts
RESV rcvfrom: 10.0.79.2 (so-0/0/1.0) 0 pkts
Explct route: 10.0.79.2 10.0.59.1
Record route: 10.0.17.13 <self> 10.0.79.2 10.0.59.1
Label in: 100752, Label out: 100368
Total 1 displayed, Up 1, Down 0
Meaning
The sample output from R7 shows the same information as for a regular transit router used in the primary path of the LSP: the ingress address (192.168.1.1), the egress address (192.168.5.1 ), and the name of the LSP (r1-to-r5). Two detour paths are displayed; the first to avoid R4 (192.168.4.1) and the second to avoid R2 (192.168.2.1). Because R7 is used as a transit router by R2 and R4, R7 can merge the detour paths together as indicated by the identical Label out value (100368) for both detour paths. Whether R7 receives traffic from R4 with a label value of 100736 or from R2 with a label value of 100752, R7 forwards the packet to R5 with a label value of 100368.
Sample Output
The following sample output is from R9, which is a router used in the detour path in the network shown in Figure 5:
user@R9> show rsvp session transit detail
Transit RSVP: 1 sessions, 1 detours
192.168.5.1
From: 192.168.1.1, LSPstate: Up, ActiveRoute: 1
LSPname: r1-to-r5, LSPpath: Primary
Suggested label received: -, Suggested label sent: -
Recovery label received: -, Recovery label sent: 3
Resv style: 1 FF, Label in: 100352, Label out: 3
Time left: 141, Since: Wed May 10 16:16:40 2006
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Port number: sender 5 receiver 9216 protocol 0
Detour branch from 10.0.49.1, to skip 192.168.5.1, Up
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Adspec: received MTU 1500
Path MTU: received 0
PATH rcvfrom: 10.0.49.1 (so-0/0/3.0) 183 pkts
Adspec: received MTU 1500 sent MTU 1500
PATH sentto: 10.0.59.1 (so-0/0/0.0) 182 pkts
RESV rcvfrom: 10.0.59.1 (so-0/0/0.0) 183 pkts
Explct route: 10.0.59.1
Record route: 10.0.12.13 10.0.24.1 10.0.49.1 <self> 10.0.59.1
Label in: 100352, Label out: 3
Detour branch from 10.0.27.1, to skip 192.168.4.1, Up
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Adspec: received MTU 1500
Path MTU: received 0
Detour branch from 10.0.17.13, to skip 192.168.2.1, Up
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Adspec: received MTU 1500
Path MTU: received 0
PATH rcvfrom: 10.0.79.1 (so-0/0/1.0) 181 pkts
Adspec: received MTU 1500
PATH sentto: 10.0.59.1 (so-0/0/0.0) 0 pkts
RESV rcvfrom: 10.0.59.1 (so-0/0/0.0) 0 pkts
Explct route: 10.0.59.1
Record route: 10.0.12.13 10.0.27.1 10.0.79.1 <self> 10.0.59.1
Label in: 100368, Label out: 3
Total 1 displayed, Up 1, Down 0
Meaning
The sample output from R9 shows that R9 is the penultimate router for the detour path, the explicit route includes only the egress link address (10.0.59.1), and the Label out value (3) indicates that R9 has performed penultimate-hop label popping. Also, the detour branch from 10.0.27.1 does not include path information because R7 has merged the detour paths from R2 and R4. Notice that the Label out value in the detour branch from 10.0.17.13 is 100368, the same value as the Label out value on R7.
Sample Output
The following sample output is from the egress router R5 in the network shown in Figure 5:
user@R5> show rsvp session egress detail
Egress RSVP: 1 sessions, 1 detours
192.168.5.1
From: 192.168.1.1, LSPstate: Up, ActiveRoute: 0
LSPname: r1-to-r5, 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: 119, Since: Thu May 11 14:44:31 2006
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Port number: sender 1 receiver 9230 protocol 0
FastReroute desired
PATH rcvfrom: 10.0.45.1 (so-0/0/2.0) 258 pkts
Adspec: received MTU 1500
PATH sentto: localclient
RESV rcvfrom: localclient
Record route: 10.0.12.13 10.0.24.1 10.0.45.1 <self>
Detour branch from 10.0.49.1, to skip 192.168.5.1, Up
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Adspec: received MTU 1500
Path MTU: received 0
Detour branch from 10.0.27.1, to skip 192.168.4.1, Up
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Adspec: received MTU 1500
Path MTU: received 0
Detour branch from 10.0.17.13, to skip 192.168.2.1, Up
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Adspec: received MTU 1500
Path MTU: received 0
PATH rcvfrom: 10.0.59.2 (so-0/0/0.0) 254 pkts
Adspec: received MTU 1500
PATH sentto: localclient
RESV rcvfrom: localclient
Record route: 10.0.12.13 10.0.24.1 10.0.49.1 10.0.59.2 <self>
Label in: 3, Label out: -
Total 1 displayed, Up 1, Down 0
Meaning
The sample output from R5 shows the main LSP in the Record route field and the detours through the network.
