Step 1: Configure a Standby Secondary Path

Configuring a standby secondary path is a two-part process. In the first part, you define the path, and in the second part, you specify a secondary path for the LSP that refers to the defined path.

NOTE: To configure a non-standby secondary path, simply omit the standby statement from the secondary path configuration.

To configure a standby secondary path, follow these steps:

Action

1. In configuration mode, go to the following hierarchy level:

[edit]

user@host# edit protocols mpls 

2. Configure the secondary ERO list:

[edit protocols mpls]

user@host# set path path-name destination loose

For example:

[edit protocols mpls]

user@R1# set path via-r7 10.0.17.14 loose

3. Configure the LSP and the secondary path:

[edit protocols mpls]

user@host# set label-switched-path lsp-path-name secondary secondary-name 
standby 

For example:

[edit protocols mpls]

user@R1# set label-switched-path r1-to-r4 secondary via-r7 standby 

4. Verify and commit the configuration:

[edit protocols mpls]

user@host# show

user@host# commit

The sample output below illustrates the configuration of the standby secondary path on ingress router R1 in the network shown in Figure 2.

Sample Output

[edit protocols mpls]

user@R1# show 

label-switched-path r1-to-r4 {

    to 192.168.4.1;

    ldp-tunneling;

    fast-reroute;

    primary via-r2;

    secondary via-r7 {

        standby; # Omit the standby statement to configure a non-standby secondary path

    }

}

path via-r2 {

    10.0.12.14 loose;

}

path via-r7 {

    10.0.17.14 loose;

}

[...Output truncated...]

What It Means

The sample output shows one standby secondary path via-r7, which includes the standby statement at the [edit protocols mpls label-switched-path lsp-path-name secondary secondary-name] hierarchy level. The standby secondary path is defined in the path statement path via-r7 and specifies a loose hop, indicating that the route taken from the previous router to this router need not be a direct path, can include other routers, and can be received on any interface.

If you have many secondary paths configured for an LSP, and you want them all to be standby, include the standby statement one level up in the hierarchy, at the [edit protocols mpls label-switched-path lsp-path-name] hierarchy level, as shown in the sample output below.

[edit protocols mpls]

user@R1# show 

label-switched-path r1-to-r4 {

    to 192.168.4.1;

    standby; # Standby configured at the label-switched-path level of the hierarchy

    primary via-r2;

    }

    secondary via-r7;

    }

}

[...Output truncated...]

For more information on configuring a secondary path, see the JUNOS MPLS Applications Configuration Guide.