Related Documentation
Example: Configuring SRLG With Link Protection
This example shows how to configure SRLG with link protection without the exclude-srlg option.
Requirements
This example uses the following hardware and software components:
- M Series, MX Series, or T Series devices
- Junos OS Release 11.4 or later running on all the devices
Overview
In this example, PE1 is the ingress router and PE2 is the egress router. P1, P2, and P3, P4, and P5 are transit routers. OSPF is configured on all the routers as the interior gateway protocol (IGP). SRLG is configured on all seven routers. The link P1>PE2 (primary path) and the link P2>PE2 belong to SRLG srlg-a.
You configure link protection for the interface P1>PE2 by including the link-protection statement.
When SRLG srlg-a is configured on the link P1>PE2 and P2>PE2, the bypass takes the longer path P1>P4>P5>PE2, not selecting the link P2>PE2 because of the added SRLG cost for srlg-a.

Configuration
CLI Quick Configuration
To quickly configure this section of the example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
Router PE1
Router P1
Router P2
Router P3
Router P4
Router P5
Router PE2
Configuring Device PE1
Step-by-Step Procedure
The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see the CLI User Guide.
To configure the ingress router PE1:
- Configure the device interfaces.[edit interfaces]user@PE1# set ge-0/0/1 unit 0 family inet address 192.168.12.1/24user@PE1# set ge-0/0/1 unit 0 family mplsuser@PE1# set ge-0/0/2 unit 0 family inet address 192.168.13.1/24user@PE1# set ge-0/0/2 unit 0 family mplsuser@PE1# set ge-0/0/3 unit 0 family inet address 192.168.14.1/24user@PE1# set ge-0/0/3 unit 0 family mplsuser@PE1# set lo0 unit 0 family inet address 10.255.0.1/32
- Configure OSPF on the interfaces.[edit protocols ospf]user@PE1# set traffic-engineeringuser@PE1# set area 0.0.0.0 interface ge-0/0/1.0user@PE1# set area 0.0.0.0 interface ge-0/0/2.0user@PE1# set area 0.0.0.0 interface ge-0/0/3.0user@PE1# set area 0.0.0.0 interface lo0.0
- Configure the SRLG definitions.[edit routing-options]user@PE1# set routing-options srlg srlg-a srlg-value 101user@PE1# set routing-options srlg srlg-a srlg-cost 10
- Configure MPLS and the LSPs and configure link protection
for the pe1-pe2 LSP.[edit protocols mpls]user@PE1# set interface ge-0/0/1.0user@PE1# set interface ge-0/0/2.0user@PE1# set interface ge-0/0/3.0user@PE1# set optimize-timer 120user@PE1# set label-switched-path pe1-pe2 to 10.255.0.7user@PE1# set protocols mpls label-switched-path pe1-pe2 link-protectionuser@PE1# set label-switched-path pe1-pe2 primary via-p1user@PE1# set label-switched-path pe1-pe2 secondary path2 standbyuser@PE1# set path via-p1 10.255.0.2 strictuser@PE1# set path path2
- Enable RSVP on the interfaces.[edit protocols rsvp]user@PE1# set interface ge-0/0/1.0user@PE1# set interface ge-0/0/2.0user@PE1# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces, show protocols ospf, show routing-options, show protocols mpls, and show protocols rsvp commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P1
Step-by-Step Procedure
The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see the CLI User Guide.
To configure device P1:
- Configure the device interfaces.[edit interfaces]user@P1# set ge-0/0/1 unit 0 family inet address 192.168.12.2/24user@P1# set ge-0/0/1 unit 0 family mplsuser@P1# set ge-0/0/2 unit 0 family inet address 192.168.27.2/24user@P1# set ge-0/0/2 unit 0 family mplsuser@P1# set ge-0/0/3 unit 0 family inet address 192.168.23.2/24user@P1# set ge-0/0/3 unit 0 family mplsuser@P1# set ge-0/0/4 unit 0 family inet address 192.168.25.2/24user@P1# set ge-0/0/4 unit 0 family mplsuser@P1# set lo0 unit 0 family inet address 10.255.0.2/32
- Configure OSPF on the interfaces.[edit protocols ospf]user@P1# set traffic-engineeringuser@P1# set area 0.0.0.0 interface ge-0/0/1.0user@P1# set area 0.0.0.0 interface ge-0/0/2.0user@P1# set area 0.0.0.0 interface ge-0/0/3.0user@P1# set area 0.0.0.0 interface ge-0/0/4.0user@P1# set area 0.0.0.0 interface lo0.0
- Configure the SRLG definitions.[edit routing-options]user@P1# set routing-options srlg srlg-a srlg-value 101user@P1# set routing-options srlg srlg-a srlg-cost 10
- Configure MPLS on the interfaces and associate the SRLG srlg-a with interface ge-0/0/2.0 for
the P1>PE2 link.[edit protocols mpls]user@P1# set interface ge-0/0/1.0user@P1# set interface ge-0/0/2.0 srlg srlg-auser@P1# set interface ge-0/0/3.0user@P1# set interface ge-0/0/4.0
- Enable RSVP on the interfaces and configure link-protection for interface ge-0/0/2.0.[edit protocols rsvp]user@P1# set interface ge-0/0/1.0user@P1# set interface ge-0/0/2.0 link-protectionuser@P1# set interface ge-0/0/3.0user@P1# set interface ge-0/0/4.0
Results
From configuration mode, confirm your configuration by entering the show interfaces, show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P2
Step-by-Step Procedure
The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see the CLI User Guide.
To configure P2:
- Configure the device interfaces.[edit interfaces]user@P2# set ge-0/0/1 unit 0 family inet address 192.168.13.3/24user@P2# set ge-0/0/1 unit 0 family mplsuser@P2# set ge-0/0/2 unit 0 family inet address 192.168.37.3/24user@P2# set ge-0/0/2 unit 0 family mplsuser@P2# set ge-0/0/3 unit 0 family inet address 192.168.23.3/24user@P2# set ge-0/0/3 unit 0 family mplsuser@P2# set lo0 unit 0 family inet address 10.255.0.3/32
- Configure OSPF on the interfaces.[edit protocols ospf]user@P2# set traffic-engineeringuser@P2# set area 0.0.0.0 interface ge-0/0/1.0user@P2# set area 0.0.0.0 interface ge-0/0/2.0user@P2# set area 0.0.0.0 interface ge-0/0/3.0user@P2# set area 0.0.0.0 interface lo0.0
- Configure the SRLG definitions.[edit routing-options]user@P2# set routing-options srlg srlg-a srlg-value 101user@P2# set routing-options srlg srlg-a srlg-cost 10
- Configure MPLS on the interfaces and associate the SRLG srlg-a with interface ge-0/0/2.0 for
the P2>PE2 link.[edit protocols mpls]user@P2# set interface ge-0/0/1.0user@P2# set interface ge-0/0/2.0 srlg srlg-auser@P2# set interface ge-0/0/3.0
- Enable RSVP on the interfaces.[edit protocols rsvp]user@P2# set interface ge-0/0/1.0user@P2# set interface ge-0/0/2.0user@P2# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces, show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P3
Step-by-Step Procedure
The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see the CLI User Guide.
To configure P3:
- Configure the device interfaces.[edit interfaces]user@P3# set ge-0/0/1 unit 0 family inet address 192.168.14.4/24user@P3# set ge-0/0/1 unit 0 family mplsuser@P3# set ge-0/0/2 unit 0 family inet address 192.168.45.4/24user@P3# set ge-0/0/2 unit 0 family mplsuser@P3# set lo0 unit 0 family inet address 10.255.0.4/32
- Configure OSPF on the interfaces.[edit protocols ospf]user@P3# set traffic-engineeringuser@P3# set area 0.0.0.0 interface ge-0/0/1.0user@P3# set area 0.0.0.0 interface ge-0/0/2.0user@P3# set area 0.0.0.0 interface lo0.0
- Configure the SRLG definitions.[edit routing-options]user@P3# set routing-options srlg srlg-a srlg-value 101user@P3# set routing-options srlg srlg-a srlg-cost 10
- Configure MPLS on the interfaces.[edit protocols mpls]user@P3# set interface ge-0/0/1.0user@P3# set interface ge-0/0/2.0
- Enable RSVP on the interfaces.[edit protocols rsvp]user@P3# set interface ge-0/0/1.0user@P3# set interface ge-0/0/2.0
Results
From configuration mode, confirm your configuration by entering the show interfaces, show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P4
Step-by-Step Procedure
The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see the CLI User Guide.
To configure P4:
- Configure the device interfaces.[edit interfaces]user@P4# set ge-0/0/1 unit 0 family inet address 192.168.45.5/24user@P4# set ge-0/0/1 unit 0 family mplsuser@P4# set ge-0/0/2 unit 0 family inet address 192.168.56.5/24user@P4# set ge-0/0/2 unit 0 family mplsuser@P4# set ge-0/0/3 unit 0 family inet address 192.168.25.5/24user@P4# set ge-0/0/3 unit 0 family mplsuser@P4# set lo0 unit 0 family inet address 10.255.0.5/32
- Configure OSPF on the interfaces.[edit protocols ospf]user@P4# set traffic-engineeringuser@P4# set area 0.0.0.0 interface ge-0/0/1.0user@P4# set area 0.0.0.0 interface ge-0/0/2.0user@P4# set area 0.0.0.0 interface ge-0/0/3.0user@P4# set area 0.0.0.0 interface lo0.0
- Configure the SRLG definitions.[edit routing-options]user@P4# set routing-options srlg srlg-a srlg-value 101user@P4# set routing-options srlg srlg-a srlg-cost 10
- Configure MPLS on the interfaces.[edit protocols mpls]user@P4# set interface ge-0/0/1.0user@P4# set interface ge-0/0/2.0user@P4# set interface ge-0/0/3.0
- Enable RSVP on the interfaces.[edit protocols rsvp]user@P4# set interface ge-0/0/1.0user@P4# set interface ge-0/0/2.0user@P4# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces, show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P5
Step-by-Step Procedure
The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see the CLI User Guide.
To configure P5:
- Configure the device interfaces.[edit interfaces]user@P5# set ge-0/0/1 unit 0 family inet address 192.168.56.6/24user@P5# set ge-0/0/1 unit 0 family mplsuser@P5# set ge-0/0/2 unit 0 family inet address 192.168.67.6/24user@P5# set ge-0/0/2 unit 0 family mplsuser@P5# set lo0 unit 0 family inet address 10.255.0.6/32
- Configure OSPF on the interfaces.[edit protocols ospf]user@P5# set traffic-engineeringuser@P5# set area 0.0.0.0 interface ge-0/0/1.0user@P5# set area 0.0.0.0 interface ge-0/0/2.0user@P5# set area 0.0.0.0 interface lo0.0
- Configure the SRLG definitions.[edit routing-options]user@P5# set routing-options srlg srlg-a srlg-value 101user@P5# set routing-options srlg srlg-a srlg-cost 10
- Configure MPLS on the interfaces.[edit protocols mpls]user@P5# set interface ge-0/0/1.0user@P5# set interface ge-0/0/2.0
- Enable RSVP on the interfaces.[edit protocols rsvp]user@P5# set interface ge-0/0/1.0user@P5# set interface ge-0/0/2.0
Results
From configuration mode, confirm your configuration by entering the show interfaces, show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.
If you are done configuring the device, enter commit from configuration mode.
Configuring Device PE2
Step-by-Step Procedure
The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see the CLI User Guide.
To configure PE2:
- Configure the device interfaces.[edit interfaces]user@PE2# set ge-0/0/1 unit 0 family inet address 192.168.27.7/24user@PE2# set ge-0/0/1 unit 0 family mplsuser@PE2# set ge-0/0/2 unit 0 family inet address 192.168.37.7/24user@PE2# set ge-0/0/2 unit 0 family mplsuser@PE2# set ge-0/0/3 unit 0 family inet address 192.168.67.7/24user@PE2# set ge-0/0/3 unit 0 family mplsuser@PE2# set lo0 unit 0 family inet address 10.255.0.7/32
- Configure OSPF on the interfaces.[edit protocols ospf]user@PE2# set traffic-engineeringuser@PE2# set area 0.0.0.0 interface ge-0/0/1.0user@PE2# set area 0.0.0.0 interface ge-0/0/2.0user@PE2# set area 0.0.0.0 interface ge-0/0/3.0user@PE2# set area 0.0.0.0 interface lo0.0
- Configure the SRLG definitions.[edit routing-options]user@PE2# set routing-options srlg srlg-a srlg-value 101user@PE2# set routing-options srlg srlg-a srlg-cost 10
- Configure MPLS on the interfaces.[edit protocols mpls]user@PE2# set interface ge-0/0/1.0user@PE2# set interface ge-0/0/2.0user@PE2# set interface ge-0/0/3.0
- Enable RSVP on the interfaces.[edit protocols rsvp]user@PE2# set interface ge-0/0/1.0user@PE2# set interface ge-0/0/2.0user@PE2# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces, show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.
If you are done configuring the device, enter commit from configuration mode.
Verification
Confirm that the configuration is working properly.
Verifying the SRLG Cost Is Added to the TE Link
Purpose
Verify that the SRLG cost is added to the TE link if it belongs to the SRLG of the protected link. Issue the show ted link detail and show rsvp session extensive bypass commands on device P1.
Action
user@P1> show ted link detail
... 10.255.0.2->192.168.27.7-1, Local: 192.168.27.2, Remote: 0.0.0.0 Local interface index: 0, Remote interface index: 0 LocalPath: 0, Metric: 1, StaticBW: 1000Mbps, AvailBW: 1000Mbps Color: 0 <none> SRLGs: srlg-a localBW [0] 0bps [1] 0bps [2] 0bps [3] 0bps localBW [4] 0bps [5] 0bps [6] 0bps [7] 0bps [...] 10.255.0.3->192.168.37.7-1, Local: 192.168.37.3, Remote: 0.0.0.0 Local interface index: 0, Remote interface index: 0 LocalPath: 0, Metric: 1, StaticBW: 1000Mbps, AvailBW: 1000Mbps Color: 0 <none> SRLGs: srlg-a localBW [0] 0bps [1] 0bps [2] 0bps [3] 0bps localBW [4] 0bps [5] 0bps [6] 0bps [7] 0bps ...
user@P1> show rsvp session extensive
bypass
Ingress RSVP: 1 sessions 10.255.0.7 From: 10.255.0.2, LSPstate: Up, ActiveRoute: 0 LSPname: Bypass->192.168.27.7 LSPtype: Static Configured Suggested label received: -, Suggested label sent: - Recovery label received: -, Recovery label sent: 299776 Resv style: 1 SE, Label in: -, Label out: 299776 Time left: -, Since: Fri Oct 21 13:19:21 2011 Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500 Port number: sender 1 receiver 52081 protocol 0 Type: Bypass LSP Number of data route tunnel through: 1 Number of RSVP session tunnel through: 0 PATH rcvfrom: localclient Adspec: sent MTU 1500 Path MTU: received 1500 PATH sentto: 192.168.25.5 (ge-0/0/4.0) 26 pkts RESV rcvfrom: 192.168.25.5 (ge-0/0/4.0) 26 pkts Explct route: 192.168.25.5 192.168.56.6 192.168.67.7 Record route: <self> 192.168.25.5 192.168.56.6 192.168.67.7 Total 1 displayed, Up 1, Down 0
Meaning
The shortest path for the bypass protecting the link P1->PE2 would have been P1->P2->PE2. Because the links P1>PE2 and P2>PE2 both belong to SRLG srlg-a, the SRLG cost of 10 for srlg-a is added to the metric for the link P2>PE2. This makes the metric for the link P2>PE2 too high to be selected for the shortest path. Therefore, the CSPF result for the computed path for the bypass becomes P1>P4>P5>PE2.