IOS XR is a release train of Cisco Systems' widely deployed Internetwork Operating System (IOS), used on their high-end Network Convergence System (NCS) and carrier-grade routers such as the ASR 9000 series and Carrier Routing System series of routers.

Cisco IOS XR
DeveloperCisco Systems
OS familyUnix-like
Working stateCurrent
Source modelClosed source
Latest release24.3.1 / September 1, 2024; 57 days ago (2024-09-01)
PlatformsNCS 5x0, NCS 5x00, 8000, ASR 9000 and XRv 9000 Series Routers
UserlandLinux
Official websiteCisco IOS XR
Line card running IOS XR.

Architecture

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According to Cisco's product literature, IOS XR shares very little infrastructure with the other IOS trains, and is instead built upon a "preemptive, memory protected, multitasking, microkernel-based operating system".[1] The microkernel was formerly provided by QNX;[2] versions 6.0 up to 7.5.2 use the Wind River Linux distribution.[3] From version 7.6.1 and onwards, the kernel has been switched to OpenEmbedded.

IOS XR aims to provide the following advantages over the earlier IOS trains:

  • Improved high availability (largely through support for hardware redundancy and fault containment methods such as protected memory spaces for individual processes and process restartability)
  • Better scalability for large hardware configurations (through a distributed software infrastructure and a two-stage forwarding architecture)
  • A package based software distribution model (allowing optional features such as multicast routing and MPLS to be installed and removed while the router is in service)
  • The ability to install package upgrades and patches (potentially while the router remains in service)
  • A web-based GUI for system management (making use of a generic, XML management interface)

History

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IOS XR was announced along with the CRS-1 in May 2004.[4] The first generally available version was 2.0.

Some significant releases include the following.

  • 3.2 – first generally available version for the 12000 router series
  • 3.9 – first generally available version for the ASR 9000 router series
  • 5.0 – first generally available version for the NCS6000 series, which is based upon a Linux kernel instead of QNX, and was released in September 2013[5]
  • 6.1.1 - Introduces support for the 64-bit Linux-based IOS XR operating system on ASR 9000 series [6]

Differences between IOS and IOS XR

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An example BGP configuration for IOS and IOS XR is shown.

More examples can be found in the Cisco document Converting Cisco IOS Configurations to Cisco IOS XR Configurations.[7]

IOS

router bgp 109
  no synchronization
  bgp log-neighbor-changes
  neighbor 203.0.113.1 remote-as 109
  neighbor 203.0.113.1 update-source Loopback0
  no auto-summary

IOS XR

router bgp 109
  neighbor 203.0.113.1
    remote-as 109
    update-source Loopback0

See also

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References

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  1. ^ "Products & Services". Cisco.
  2. ^ QNX press release Confirming use of their microkernel in IOS XR
  3. ^ "Cisco IOS XR Software Release 6.0 Operational Enhancements Data Sheet". Cisco.
  4. ^ "Cisco press release announcing CRS-1 and IOS XR". Archived from the original on March 9, 2005.
  5. ^ "Release Notes for Cisco NCS 6000 Series Routers, Release 5.0.0". Cisco.
  6. ^ "Release Notes for Cisco ASR 9000 Series Aggregation Services Routers, Release 6.1.2".
  7. ^ "Converting Cisco IOS Configurations to Cisco IOS XR Configurations" (PDF). cisco.com. Cisco Systems. Retrieved August 4, 2017.
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