Preface

From Release 6.1.2 onwards, Cisco introduces support for the 64-bit Linux-based IOS XR operating system. Extensive feature parity is maintained between the 32-bit and 64-bit environments. Unless explicitly marked otherwise, the contents of this document are applicable for both the environments. For more details on Cisco IOS XR 64 bit, refer to the Release Notes for Cisco ASR 9000 Series Routers, Release 6.1.2 document.

This guide describes the Cisco IOS XR QoS configurations. The preface for the Modular QoS Configuration Guide for Cisco ASR 9000 Series Routers contains these sections:

Changes to this Document

This table lists the changes made to this document since it was first published.

Date

Summary

June 2026

Republished for Release 26.2.1.

March 2026

Initial release of this document

Communications, Services, and Additional Information

  • To receive timely, relevant information from Cisco, sign up at Cisco Profile Manager.

  • To get the business results you’re looking for with the technologies that matter, visit Cisco Services.

  • To submit a service request, visit Cisco Support.

  • To discover and browse secure, validated enterprise-class apps, products, solutions and services, visit Cisco Marketplace.

  • To obtain general networking, training, and certification titles, visit Cisco Press.

  • To find warranty information for a specific product or product family, access Cisco Warranty Finder.

Cisco Bug Search Tool

Cisco Bug Search Tool (BST) is a web-based tool that acts as a gateway to the Cisco bug tracking system that maintains a comprehensive list of defects and vulnerabilities in Cisco products and software. BST provides you with detailed defect information about your products and software.