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Table of Contents Expand all

play_arrow OSPF Overview
- Introduction to OSPF
play_arrow Understand OSPF Configurations
- Understanding OSPF Configurations
play_arrow Configure OSPF Interfaces
- Configuring OSPF Interfaces
play_arrow Configure OSPF Areas
- Configuring OSPF Areas
play_arrow Configure OSPF Route Control
- Configuring OSPF Route Control
play_arrow Configure OSPF Authentication
- Configuring OSPF Authentication
play_arrow Configure OSPF Routing Instances
play_arrow Configure OSPF Timers
- Configuring OSPF Timers
play_arrow Configure OSPF Fault Detection using BFD
- Configuring OSPF Fault Detection using BFD
play_arrow Configure Graceful Restart for OSPF
- Configuring Graceful Restart for OSPF
play_arrow Configure Loop-Free Alternate Routes for OSPF
- Configuring Loop-Free Alternate Routes for OSPF
play_arrow Configure OSPF Support for Traffic Engineering
play_arrow Configure OSPF Database Protection
- Configuring OSPF Database Protection
play_arrow Configure OSPF Routing Policy
- Configuring OSPF Routing Policy
play_arrow Configure OSPFv2 Sham Links
- Configuring OSPFv2 Sham Links
play_arrow Configure OSPF on Logical Systems
- Configuring OSPF on Logical Systems
play_arrow Troubleshooting Network Issues
- Troubleshooting Network Issues
play_arrow Verifying and Monitoring OSPF
- Verifying and Monitoring OSPF Configuration
play_arrow Configuration Statements and Operational Commands
- [OBSOLETE] show ospf spring sensor info
- Junos CLI Reference Overview

list Table of Contents

English

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Configuring Application-Specific Link Attribute on an OSPF Interface

date_range 22-Nov-23

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Starting in Junos OS and Junos OS Evolved Release 22.2R1, you can advertise different te-attributes such as te-metric, delay-metric, or admin-groups for RSVP and flexible algorithms on the same link. This is done using flexible algorithm specific application-specific link attribute as defined in RFC 8920.

To configure application-specific link attribute based flexible algorithm on an OSPF Interface:

Create an OSPF area.

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[edit protocols]
user@host#set protocols ospf area area-id

For example:

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[edit protocols]
user@host#set protocols ospf area 0.0.0.0

Specify the interface.

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[edit protocols ospf area 0.0.0.0]
user@host#set interface interface-name

For example:

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[edit protocols ospf area 0.0.0.0]
user@host#set interface ge-0/0/0.0

Configure application-specific link attribute on the OSPF interface of the device.
```
[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0]
user@host#set application-specific
```

Specify the attribute group.

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[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific]
user@host#set attribute-group name

For example:

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[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific]
user@host#set attribute-group asla

Configure flexible algorithm specific te-attributes such as te-metric, delay-metric, and admin-groups. Specify the te-metric for the attribute group. The te-metric indicates the metric type based on which OSPFv2 calculates the path.
```
[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific attribute-group asla]
user@host#set te-metric
```
For example:
```
[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific]
user@host#set 15
```

Specify the admin-group for the attribute group.

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[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific attribute-group asla]
user@host#set admin-group

For example:

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[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific]
user@host#set green

Specify delay-metric for the attribute group.

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[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific attribute-group asla]
user@host#set delay-metric

For example:

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[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific]
user@host#set 123123

In case delay-metric is not configured, specify advertise-interface-delay to fetch the delay values from the interface configuration hierarchy, that is legacy delay values.
```
[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific attribute-group asla]
user@host#set advertise-interface-delay
```
For example:
```
[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific]
user@host#set 123125
```
Note:
The following configuration can be committed only if all of the following criteria match:

An application is associated with the attribute group.

Delay-metric is not configured in the hierarchy.

Interface level delay configurations are present.
Specify the application for the attribute group. In the current implementation, only flexible algorithm can be configured as an application. An attribute group can have more than one applications associated with it and it equates to a single application-specific link attribute with the application bits set in the standard application identifier bit mask field of the application-specific link attribute sub.
```
[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific attribute-group asla]
user@host#set application aplication-name
```
```
[edit protocols ospf area 0.0.0.0 interface ge-0/0/0.0 application-specific attribute-group asla]
user@host#set application flex-algorithm
```
Enter commit from the configuration mode.
Specify strict-asla-based-flex-algorithm to mandate that flexible algorithm path computations use only the links which advertise relevant te-attributes through application-specific link attribute.
```
[edit protocols ospf source-packet-routing]
user@host#set strict-asla-based-flex-algorithm
```

Enter commit from the configuration mode.

To verify your configuration results, use the show protocols operational command.

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ospf {
          area 0.0.0.0
             interface ge-0/0/0.0 {
                    application-specific {
                          attribute-group asla {
                                      te-metric 15;
                                      admin-group green;
                                       delay-metric 123123;
                                       advertise-interface-delay;   
                                       application flex-algorithm;

                           }
                    }
            }
          source-packet-routing {
          strict-asla-based-flex-algorithm;
      }
}
 

The Junos OS and Junos OS Evolved implementation supports application-specific link attribute subTLV to comply with RFC 8920. The application-specific link attribute sub-TLV is a sub-TLV of the OSPFv2 extended Link TLV as defined in RFC 7684.

To verify the presence of application-specific link attribute sub-TLVs in the OSPF database use the show ospf database extensive operational command.

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user@host> show ospf database advertising-router self extensive lsa-id 10.0.0.2

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OSPF database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
OpaqArea*10.0.0.2          100.100.100.100  0x80000007   665  0x22 0x649d 104
Opaque LSA
  Extended Link (1), length 80:
    Link Type (1), length 1:
     1
     Link Id (2), length 4:
     10.1.1.1
     Link Data (3), length 4:
     10.21.1.1
    Adjacency Sid (2), length 7:
        Flags (1), length 1:
          0x60
        MT ID (2), length 1:
           0
        Weight (3), length 1:
           0
        Label (4), length 3:
          17
    Application Specific Link Attribute (10), length 52:
        SABM Length (1), length 1:
          4
        UDABM Length (2), length 1:
          0
        SABM (3), length 4:
          0x10
        UDABM (4), length 0:
          0x0
    TEMetric (5), length 4:
      10
    UnidirecLinkDelay (27), length 4:
      123
    MinMaxUnidirecLinkDelay (28), length 8:
      Min DM: 123, Max DM: 123
    UnidirecLinkDelayVar (29), length 4:
      0
    Color (9), length 4:
      2
  Gen timer 00:34:55
  Aging timer 00:48:55
  Installed 00:11:05 ago, expires in 00:48:55, sent 00:11:05 ago
  Last changed 00:11:05 ago, Change count: 6, Ours, TE Link ID: 0

The output displays application-specific link attribute sub-TLV fields and attributes.

arrow_backward PREVIOUS How to Configure Flexible Algorithms in OSPF for Segment Routing Traffic Engineering

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OSPF User Guide

Configuring Application-Specific Link Attribute on an OSPF Interface

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Configuring Application-Specific Link Attribute on an OSPF Interface

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