OSPF Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

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OSPF Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

About this content

Outlines the release history and update summary for the OSPF Configuration Guide. It enables users to access the latest IOS XR features and release information through a centralized, continuously updated resource.


Getting Started

This cumulative guide provides a single, continuously updated version that includes all the latest IOS XR features and release updates. It simplifies your experience by letting you bookmark one link and access the complete guide, instead of navigating through multiple release-specific versions.

Specific changes or updates tied to individual releases are clearly called out within the relevant sections. For a list of features introduced in a specific release, refer to the Release Notes.

The table lists the release numbers for which this document has been updated since its initial publication.

Table 1. Changes to this document
Date Summary

June 2026

First published for Release 26.2.1

Getting Started

Outlines the release history and update summary for the OSPF Configuration Guide. It enables users to access the latest IOS XR features and release information through a centralized, continuously updated resource.

OSPF fundamentals and basic configuration

Explains OSPFv2 and OSPFv3 requirements, implementation features, and routing processes, and describes how to enable and verify OSPF routing on Cisco IOS XR routers.

OSPF areas, neighbors, and route-control

Explains how OSPF areas, router roles, neighbors, designated routers, route advertisements, and timers support scalable routing, and describes how to configure area types, nonbroadcast neighbors, LSA frequency, default routes, and route redistribution.

OSPF security and high availability

Explains how authentication, BFD strict mode, graceful restart, nonstop routing, and nonstop forwarding protect OSPF exchanges, preserve adjacencies, and minimize routing disruption during process restarts and route processor failovers.

OSPF optimization scale and fast-reroute

Describes how SPF scheduling, prefix prioritization, topology controls, route summarization, resource-protection mechanisms, and loop-free alternates improve OSPF scalability, convergence, and traffic protection during topology changes and link failures.

OSPF advanced integrations

Explains how virtual and sham links maintain OSPF connectivity and optimize MPLS VPN routing, and describes integrations with LDP, MPLS Traffic Engineering, VRFs, route redistribution, management interfaces, and security mechanisms.