OSPFv3 Max-Metric Router LSA

The Open Shortest Path First version 3 (OSPFv3) max-metric router link-state advertisement (LSA) feature enables OSPFv3 to advertise its locally generated router LSAs with a maximum metric. The feature allows OSPFv3 processes to converge but not attract transit traffic through the device if there are better alternate paths.

Information About OSPFv3 Max-Metric Router LSA

OSPFv3 Max-Metric Router LSA

The OSPFv3 max-metric router LSA feature enables OSPFv3 to advertise its locally generated router LSAs with a maximum metric. The feature allows OSPFv3 processes to converge but not attract transit traffic through the device if there are better alternate paths. After a specified timeout or a notification from Border Gateway Protocol (BGP), OSPFv3 advertises the LSAs with normal metrics.

The max-metric LSA control places the OSPFv3 router into the stub router role using its LSA advertisement. A stub router only forwards packets destined to go to its directly connected links. In OSPFv3 networks, a device could become a stub router by advertising large metrics for its connected links, so that the cost of a path through this device becomes larger than that of an alternative path. OSPFv3 stub router advertisement allows a device to advertise the infinity metric (0xFFFF) for its connected links in router LSAs and advertise the normal interface cost if the link is a stub network.

How to Configure OSPFv3 Max-Metric Router LSA

Configuring the OSPFv3 Max-Metric Router LSA

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. router ospfv3 process-id
  4. address-family ipv6 unicast
  5. max-metric router-lsa [external-lsa [max-metric-value ]] [include-stub ] [inter-area-lsas [max-metric-value ]] [on-startup {seconds | wait-for-bgp }] [prefix-lsa ] [stub-prefix-lsa [max-metric-value ]] [summary-lsa [max-metric-value ]]
  6. end
  7. show ospfv3 [process-id ] max-metric

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

router ospfv3 process-id

Example:


Device(config)# router ospfv3 1

Enables OSPFv3 router configuration mode.

Step 4

address-family ipv6 unicast

Example:


Device(config)# address-family ipv6 unicast

Configures an instance of the OSPFv3 process in the IPv6 address family.

Step 5

max-metric router-lsa [external-lsa [max-metric-value ]] [include-stub ] [inter-area-lsas [max-metric-value ]] [on-startup {seconds | wait-for-bgp }] [prefix-lsa ] [stub-prefix-lsa [max-metric-value ]] [summary-lsa [max-metric-value ]]

Example:


Device(config-router-af)# max-metric router-lsa on-startup wait-for-bgp

Configures a device that is running the OSPFv3 protocol to advertise a maximum metric so that other devices do not prefer the device as an intermediate hop in their SPF calculations.

Step 6

end

Example:


Device(config-router-af)# end

Exits address family configuration mode and returns to privileged EXEC mode.

Step 7

show ospfv3 [process-id ] max-metric

Example:


Device# show ospfv3 1 max-metric

Displays OSPFv3 maximum metric origination information.

Configuration Examples for OSPFv3 Max-Metric Router LSA

Example: Verifying the OSPFv3 Max-Metric Router LSA

Router# show ipv6 ospf max-metric 

            OSPFv3 Router with ID (192.1.1.1) (Process ID 1)

 Start time: 00:00:05.886, Time elapsed: 3d02h
 Originating router-LSAs with maximum metric
    Condition: always, State: active

Additional References for OSPF Nonstop Routing

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Command List, All Releases

OSPF commands

Cisco IOS IP Routing: OSPF Command Reference

Configuring IETF NSF or Cisco NSF

“Configuring NSF-OSPF” module in the Cisco IOS High Availability Configuration Guide

Standard and RFCs

Standard/RFC

Title

RFC 2328

OSPF Version 2

RFC 3623

Graceful OSPF Restart

Technical Assistance

Description

Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html

Feature Information for OSPFv3 Max-Metric Router LSA

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 1. Feature Information for OSPFv3 Max-Metric Router LSA

Feature Name

Releases

Feature Information

OSPFv3 Max-Metric Router LSA

Cisco IOS XE Release 3.4S

The OSPFv3 max-metric router LSA feature enables OSPF to advertise its locally generated router LSAs with a maximum metric.

The following commands were introduced or modified: max-metric router-lsa , show ipv6 ospf max-metric , show ospfv3 max-metric .
Table 2. Feature Information for OSPFv3 Max-Metric Router LSA

Feature Name

Releases

Feature Information

OSPFv3 Max-Metric Router LSA

Cisco IOS XE Release 17.4

This feature was introduced.