Release Notes for Cisco IOS XRd, IOS XR Release 24.4.1

XRd is a powerful IOS XR virtual platform that supports a wide variety of technology roles such as virtual route reflector (vRR), virtual cell-site router (vCSR), and virtual provider-edge (vPE). It is available in a containerized form-factor enabling both standalone and Kubernetes-based containerized network deployments.

Cisco IOS XRd Overview

XRd is the latest virtual platform from Cisco that brings the highly scalable, feature-rich, and reliable IOS-XR operating system to containerized network deployments. With XR control plane pedigree shared with the likes of Cisco 8000 and data plane capabilities that are derived from the powerful XRv9000, XRd brings the best of both worlds - enabling high scale control plane use cases such as virtual route-reflector (vRR) and high throughput requirements in virtual provider edge (vPE).

XRd is available in two formats:

  • XRd Control Plane

  • XRd vRouter

Licensing

Starting with Cisco IOS XR Release 24.1.1, Smart Licensing Using Policy (SLP) is the default Licensing model. When you upgrade to the Cisco IOS XR Release 24.1.1 release or later, the Smart Licensing Using Policy is enabled by default.

You can migrate your devices to Smart Licensing with Policy model, see Migrating from Smart Licensing to Smart Licensing Using Policy, Smart Licensing Using Policy on Cisco IOS XR Routers.

We recommend that you update to the latest version of SSM On-Prem or Cisco Smart Licensing Utility.


Note

SSM On-Prem and CSSM both support SLP devices and SL devices. SLP devices and SL devices can coexist in a network. The Smart Licensing (SL) model is available in releases Cisco IOS XR Release 7.11.1 and earlier.

Cisco IOS XRd Licensing Model

The Cisco IOS XRd platform offers two types of licensing schemes. This table lists details of Cisco IOS XRd Router's software licenses or entitlements, arranged according to licensing PIDs.

The Cisco IOS XRd instances are pre-loaded with an evaluation license valid for 90 days. For licenses post the evaluation period, you can purchase the XRd licenses using Cisco Smart Licensing.

Table 1. Cisco IOS XRd Licensing PIDs

PIDs

Description

XRD-VR-CP

XRd Control Plane

  • XRD-VR-CP-DP-ESS

  • XRD-VR-CP-DP-ADN

XRd vRouter

What's New in Cisco IOS XR Release 24.4.1

For the complete list of features supported on Cisco IOS XRd until Cisco IOS XR Release 24.4.1, see:

For more details on the Cisco IOS XR release model and associated support, see Software Lifecycle Support Statement - IOS XR.

Software Features Enhanced and Introduced

Feature Description

Segment Routing

Far-End Delay Metrics in One-Way Measurement Mode

SR PM now enables network operators to compute both far-end (T4 – T3) and near-end (T2 – T1) delay metrics, providing a complete view of end-to-end delay across the entire data path. Measuring the far-end delay from the responder to the querier node improves visibility, and allows operators to accurately monitor and evaluate network performance.

Previously, you could not measure the far-end delay metrics for a given data path.

Fallback Delay Advertisement for Interfaces

You can now advertise fallback delay value, retaining delay information in performance metrics even when delay metrics for interfaces are temporarily unavailable due to hardware, synchronization, or network connectivity issues. The feature ensures optimal routing decisions, by maintaining network stability and continuous performance, even when real-time metrics are temporarily inaccessible.

Previously, the performance metrics did not include delay metrics when they were temporarily inaccessible, resulting in visibility gaps in the network and less effective routing.

The feature introduces these changes:

CLI:

  • The performance-measurement interface command is modified with a new advertise-delay fallback keyword.

YANG Data Models:

  • Cisco-IOS-XR-um-performance-measurement-cfg.yang

See (GitHub, Yang Data Models Navigator)

Delay and Synthetic Loss Release Measurement for GRE Tunnel Interfaces

With this feature, you can now measure the latency or delay experienced by data packets when they traverse a network, and also proactively monitor and address potential network issues before they impact users by measuring key parameters, packet loss, and jitter for GRE tunnel interfaces.

This feature enables you to report synthetic Two-Way Active Measurement Protocol (TWAMP) test packets that are deployed in delay-profile or delay measurement sessions, and enables delay measurement for GRE tunnel interfaces.

The feature introduces these changes:

CLI:

The performance-measurement interface command supports the tunnel-ip keyword.

Host Requirements

This section details the host requirements for both XRd Control Plane and XRd vRouter:

Table 2. XRd Control Plane
Parameter Requirement

XRd Control Plane Host

CPU

x86-64 CPU with at least 2 cores

RAM

4 GB

Linux kernel

Version 4.18 and above

Note

 

The Linux kernel must install the dummy and nf_tables modules.

Linux cgroups

Version 1

Note

 

Support for unified hierarchy cgroups is not available.

XRd Control Plane instance on the host

CPU

1 core minimum

RAM

2 GB minimum

Inotify user instances and watches

4000

XRd Control Plane on AWS EC2 instance

Instance Type

m5.2xlarge

Number of threads per processor core

1

Minimum Disk Size

8 GB

Note

 

A XRd instance requires the minimum disk size of 8 GB, but there may be demand for additional disk space depending on how the node handles core files.

Operating System

Amazon Linux 2 with EKS Optimizations

Kernel Settings

4000 inotify user instances and watches per XRd instance
Table 3. XRd vRouter
Parameter Requirement

XRd vRouter Host

CPU

x86-64 CPU with at least 4 cores

CPU instruction set

  • ssse3

  • sse4.1

  • sse4.2

Linux kernel

Version 4.18 and above

Note

 

The Linux kernel must install the dummy, vfio-pci or igb_uio, and nf_tables modules.

Linux cgroups

version 1

Note

 

Support for unified hierarchy cgroups is not available.

XRd vRouter instance on the host

CPU

2 minimum, 1 isolated for the dataplane use

RAM

5 GB minimum

Hugepages

3 GB minimum

Note

 

The XRd vRouter instance must enable Hugepage support with 1GB hugepage size.

Inotify user instances and watches

4000

XRd vRouter on Amazon EC2 Instance

Instance Types

  • m5.24xlarge

  • m5n.24xlarge

Number of threads per processor core

1

Minimum Disk Size

8 GB

Note

 

A XRd instance requires the minimum disk size of 8 GB, but there may be demand for additional disk space depending on how the node handles core files.

Operating System

Amazon Linux 2 with EKS Optimizations

Kernel Settings

  • 4000 inotify user instances and watches per XRd instance

  • CPU isolation settings for the required XRd deployments

Additional Kernel Modules

  • uio (from Amazon Linux 2)

  • igb_uio from dpdk-mods package with write combine mode enabled

Hugepages

6 GB

Note

 

The XRd vRouter instance must enable Hugepage support with 1GB hugepage size.

Caveats

There are no caveats in this release.

Other Important Information

Upgrading Cisco IOS XRd Software

Cisco IOS XRd software is a containerized form-factor deployment that follows the container pattern regarding software upgrades and does not support standard IOS-XR install or upgrade operations. To use the latest XRd software, you can create a new XRd instance with the latest software in place of the previous XRd instance and attach the necessary persistent state to the new XRd instance. The new XRd software may be a different version of IOS-XR or the existing version of IOS-XR with new or bugfix RPMs applied (or a combination of the two). An XRd container image containing new or bugfix RPMs is created from an existing XRd container image using standard container build tools (such as docker build or buildah) to install the new software packages to the existing base image. The apply-bugfixes script within the xrd-tools repository (https://github.com/ios-xr/xrd-tools) is available to achieve this using docker build, and you can use it as a template for other container build tools.