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difference between IOS, IOS-XE and IOS XR

Ibrahim Jamil
Level 6
Level 6

Hello Freinds


What is the  difference between IOS, IOS-XE and IOS XR


 Answer for dummys pls :)



Thanks all guys

5 Replies 5

Joseph W. Doherty
Hall of Fame
Hall of Fame
If you're familiar with OSs, think of IOS as MS-DOS, IOS-XE as DESQview or VM/386, and IOS-XR as Linux or NT.

thanks freinds

Fahad Wasi
Level 1
Level 1


IOS-XE is basically a combination of a monolithic application and a linux kernel. IOS-XE is an advanced version of IOS and pls note that both IOS and IOS-XE share a lot of codes, meaning that both have similar codes unlike IOS-XR which is based on entirely different codings.

IOS-XR is based on QNX(QNX is a Unix type OS). The applications of IOS-XR has been seperated into different processes and if any one process stops or malfunctions ,the other processes are not effected.


David Amalorpavam
Cisco Employee
Cisco Employee

Please check the below link


Dave Zacks, Distinguished Systems Engineer at Cisco, looks at the IOS-XE Evolution, which has changed from a monolithic OS, to a modularized IOS built on top of Linux. Its latest change is to deliver containerized application along side IOS, and to focus on programmability via APIs. Recorded at ...
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