Implementing Routing Policy on Cisco IOS XR Software

A routing policy instructs the router to inspect routes, filter them, and potentially modify their attributes as they are accepted from a peer, advertised to a peer, or redistributed from one routing protocol to another. Routing protocols make decisions to advertise, aggregate, discard, distribute, export, hold, import, redistribute and otherwise modify routes based on configured routing policy.

The routing policy language (RPL) has been designed to provide a single, straightforward language in which all routing policy needs can be expressed. RPL was designed to support large-scale routing configurations. It greatly reduces the redundancy inherent in previous routing policy configuration methods. RPL has been designed to streamline routing policy configuration, to reduce system resources required to store and process these configurations, and to simplify troubleshooting.

Note For more information about routing policy on the Cisco IOS XR software and complete descriptions of the routing policy commands listed in this module, see the “Related Documents” section of this module. To locate documentation for other commands that might appear during execution of a configuration task, search online in the Cisco IOS XR software master command index.

Feature History for Implementing Routing Policy on Cisco IOS XR Software

Release

Modification

Release 2.0

This feature was introduced on the Cisco CRS-1.

 

 

Release 3.0

No modification.

 

 

Release 3.2

Support was added for the Cisco XR 12000 Series Router.

 

 

Contents

Prerequisites for Implementing Routing Policy, page RC-206

Information About Implementing Routing Policy, page RC-206

How to Implement Routing Policy, page RC-237

Configuration Examples for Implementing Routing Policy, page RC-241

Additional References, page RC-244

Cisco IOS XR Routing Configuration Guide

RC-205

Page 221
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Cisco Systems manual Implementing Routing Policy on Cisco IOS XR Software, RC-205

IOS XR specifications

Cisco Systems IOS XR is an advanced operating system designed specifically for high-performance routers and service provider networks. It serves as the backbone for many of Cisco's high-end routing platforms, enabling service providers to manage their networks with increased efficiency, flexibility, and scalability.

One of the main features of IOS XR is its modular architecture. This allows for the independent operation of various components within the OS, facilitating the deployment of new features and updates without affecting the overall stability of the system. This modularity ensures that service providers can implement rapid changes and enhancements while maintaining service continuity.

Another characteristic of IOS XR is its support for 64-bit architecture, which provides enhanced performance and the ability to manage larger amounts of data. This is particularly beneficial for service providers that deal with high traffic volumes and require robust data processing capabilities. The utilization of 64-bit technology also enables the operating system to utilize memory more efficiently, allowing for greater scalability.

IOS XR incorporates advanced technologies such as Distributed System Architecture (DSA) and Multiple Routing Instances (Merging Routes). DSA allows for the distribution of routing processes across multiple hardware resources, maximizing performance and redundancy. Multiple Routing Instances enable operators to create separate logical routing tables for different services, improving isolation and efficiency in managing network traffic.

The operating system also focuses heavily on security, featuring extensive encryption methods and access controls to safeguard network resources. IOS XR supports various authentication protocols, ensuring secure access to routers and switches. In addition, the OS includes comprehensive logging and monitoring capabilities, allowing network administrators to track activities and respond quickly to potential threats.

Another critical aspect of IOS XR is its adherence to the principles of service-oriented architecture (SOA). This approach permits the development of applications and services that can operate independently, fostering innovation and enabling service providers to tailor their offerings based on customer demands.

Ultimately, Cisco IOS XR is a powerful, reliable operating system that meets the complex needs of modern telecommunications networks. With its focus on modularity, performance, security, and scalability, it enables service providers to deliver high-quality, resilient services to their customers while efficiently managing network resources. As the industry continues to evolve, IOS XR remains a vital tool for those aiming to stay competitive in the ever-changing landscape of networking.