Segment Routing v6 Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases
Segment Routing v6 Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases
Provides comprehensive instructions for deploying and managing SRv6 on Cisco 8000 Series Routers running Cisco IOS XR, covering fundamentals, locators, micro SID, Flex-Algo, PCEP, traffic engineering, Layer 2 and Layer 3 services, SRv6-MPLS interworking, observability, migration, and OAM, with feature guidance and verification workflows.
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.
| Date | Summary |
|---|---|
|
September 2026 |
Republished for Release 26.3.1. |
|
February 2026 |
Republished for Release 26.1.1. |
|
December 2025 |
Republished for Release 25.4.1. |
|
October 2025 |
First published for Release 25.3.1. |
Explains how YANG data models enable model-driven configuration and management of SRv6 features on Cisco 8000 Series Routers through programmable interfaces.
Explains how SRv6 programs network paths and processes traffic, providing the foundational knowledge needed to understand its capabilities, operational behavior, deployment constraints, and SID management.
Explains how uSIDs improve SRv6 scalability by encoding multiple instructions within a SID carrier and guides users through allocation, deployment, configuration, and supported services.
Explains how SRv6 locators organize SID address spaces for routing and traffic steering and describes locator deployment and lightweight host routing through LLDP.
Explains how source-address entropy improves load balancing for SRv6 uSID traffic and provides the operational guidance and configuration needed to deploy it effectively.
Explains how IS-IS advertises SRv6 capabilities and locators, enabling routers to establish SRv6 forwarding paths across an IPv6 network.
Explains how SRv6 Flex-Algo customizes path selection through IS-IS and supports dual SID termination for flexible and efficient traffic steering.
Explains how TI-LFA protects SRv6 traffic during link or node failures and guides users through selecting, configuring, and verifying fast reroute protection.
Explains how PCEP provides centralized path computation and policy control for SRv6 networks, including secure sessions, policy management, timers, and redundancy.
Explains how SRv6 microloop avoidance maintains stable packet forwarding during IS-IS convergence and provides the guidance needed to configure temporary loop-free paths.
Explains how SRv6-TE policies steer traffic along intent-based paths and provides the tools needed to control, protect, monitor, and troubleshoot those paths.
Explains how SRv6 transports Layer 3 VPN and global routing services and guides users through deploying, interconnecting, and monitoring IPv4 and IPv6 services.
Describes advanced SRv6 capabilities that improve Layer 3 service flexibility, interoperability, convergence, path visibility, packet delivery, and migration across diverse network environments.
Explains how SRv6 supports resilient Layer 2 and integrated VPN services through EVPN, pseudowires, multihoming, traffic steering, and flexible SID allocation.
Explains how interworking gateways extend Layer 3 services across SRv6 and MPLS domains while preserving reachability, forwarding behavior, service quality, and migration flexibility.
Explains how SRv6 performance measurement monitors path availability, delay, and forwarding behavior to support service assurance, troubleshooting, and network optimization.
Explains how SRv6 traffic accounting collects packet and byte statistics to support traffic analysis, capacity planning, service monitoring, and network optimization.
Guides users through migrating an SRv6 network from Format 1 to uSID F3216 while maintaining service continuity across underlay and overlay networks.
Explains how to deploy SRv6 with full-length SIDs, including network programming, IS-IS resiliency, Flexible Algorithm, VPN and EVPN services, BGP-LS reporting, configuration, and OAM verification.