Cisco IOS XR

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".{{Cite web|url=https://www.cisco.com/c/en/us/products/index.html|title=Products & Services|website=Cisco}} The microkernel was formerly provided by QNX;[http://www.qnx.com/news/pr_1329_3.html QNX press release] Confirming use of their microkernel in IOS XR versions 6.0 up to 7.5.2 use the Wind River Linux distribution.{{Cite web|url=https://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/ios-xr-software/datasheet-c78-736154.html|title=Cisco IOS XR Software Release 6.0 Operational Enhancements Data Sheet|website=Cisco}} 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)

IOS XR was announced along with the CRS-1 in May 2004.{{cite web|url=http://newsroom.cisco.com/dlls/2004/prod_052504.html?CMP=ILC-001 |title=Cisco press release announcing CRS-1 and IOS XR |archiveurl=https://web.archive.org/web/20050309155945/https://newsroom.cisco.com/dlls/2004/prod_052504.html?CMP=ILC-001 |archive-date=March 9, 2005}} 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{{Cite web|url=https://www.cisco.com/c/en/us/td/docs/ios_xr_sw/iosxr_r5-0/release/notes/reln_500ncs.html|title=Release Notes for Cisco NCS 6000 Series Routers, Release 5.0.0|website=Cisco}}
• 6.1.1 - Introduces support for the 64-bit Linux-based IOS XR operating system on ASR 9000 series {{Cite web|url=http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k_r6-1/general/release/notes/b-release-note-asr9k-612.html|title = Release Notes for Cisco ASR 9000 Series Aggregation Services Routers, Release 6.1.2}}

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.{{cite web|title=Converting Cisco IOS Configurations to Cisco IOS XR Configurations|url=http://www.cisco.com/c/en/us/td/docs/ios_xr_sw/iosxr_r3-2/conversion/reference/guide/cnvt32/cn32main.pdf|website=cisco.com|publisher=Cisco Systems|accessdate=August 4, 2017}}

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

• Cisco IOS
• Cisco IOS XE
• Cisco NX-OS

• [https://content.cisco.com/welcome.html Cisco Content Hub]
• [https://cfnng.cisco.com Cisco Feature Navigator]
• [http://www.cisco.com/web/Cisco_IOS_XR_Software/index.html Cisco IOS XR Support Page]
• [https://www.cisco.com/c/en/us/support/routers/asr-9000-series-aggregation-services-routers/series.html Cisco Aggregation Services Router 9000 Series Support Page]
• [https://www.cisco.com/c/en/us/support/routers/carrier-routing-system/series.html Cisco Carrier Routing System Support Page]
• [http://www.cisco.com/en/US/products/ps5763/prod_presentation_list.html Cisco multimedia documentation] - covering IOS XR and its supported systems
• [https://sec.cloudapps.cisco.com/security/center/publicationListing.x Cisco Security Advisories]
• [http://www.uknof.org.uk/uknof11/Nisbet+Wilson-HEAnet.pdf HEAnet's New Network and Working with IOS-XR]

Category:Cisco products