IOS vs IOS XE - Show version

[paolosolari]

Hi guys, 

I get the below output from the "show version" command on a Cisco 4331 ISR:

Cisco IOS XE Software, Version 03.13.04.S - Extended Support Release
Cisco IOS Software, ISR Software (X86_64_LINUX_IOSD-UNIVERSALK9-M), Version 15.4(3)S4, RELEASE SOFTWARE (fc3)

My question, which software version is it running? 03.13.04.S or 15.4(3)S4? Why does it show both?

Cheers,

Paolo

[balaji.bandi]

Maybe never seen that output before, can you please post the complete show version - without editing (maybe removing any serial numbers)

[Leo Laohoo]

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@paolosolari wrote:

My question, which software version is it running? 03.13.04.S or 15.4(3)S4? Why does it show both?

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When Cisco was "cutting over" the old naming convention of the versions to the new IOS-XE, IOS-XE versions were often "expressed" in the classic way, like 15.4(3)S4, and the new way, like 3.13.4. 

The "give-away" is the last digit.  Classic IOS is "S4" while the IOS-XE is "4".  They are the same. 

Look at the filename of the IOS-XE file, the syntax has both classic IOS and the new IOS-XE version in it.

[paolosolari]

Ah ok I think that makes sense, so 15.4(3)S4 is the same as 3.13.4? Just a different way of writing it? 

Cheers,

Paolo