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.
Whats changed in this book
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 or the IOS XR Feature Finder.
The table lists the release numbers for which this document has been updated since its initial publication.
| Date | Summary |
|---|---|
| June 2026 |
First published for Release 26.2.1 |
Configure 400G digital coherent optics
Describes Cisco 400G Digital Coherent QSFP-DD optics support, including platform compatibility, restrictions, traffic capabilities, and key configuration, monitoring, and troubleshooting procedures.
Configure 800G optics
Provides instructions for configuring 800 Gigabit Ethernet connectivity using Cisco QSFP-DD800 optical modules, including breakout mode settings, port pairing guidelines, and support for high-capacity coherent optics on specific line cards.
Configure controllers
Describes Cisco IOS XR Optics Controller configuration, including optical module control, diagnostics, alarms, PRBS testing, and loopback procedures for monitoring and troubleshooting transceivers.
Configure QDD optical line system
Describes the Cisco QDD optical line system (OLS), including pluggable amplifier operation, DWDM deployment use cases, OTS controller configuration, safety controls, and OLS alarm troubleshooting.