Cisco IOS Versons

[harrisfed]

I need to update a couple of WS-C3850-24T-S switches but I see two totally differnet version numbers on the download site:

3.6.4E to 16.2.2

Which one is correct?

Whats the difference?

[ahmedshoaib]

Hi;

Always go with the Cisco suggested/recommended IOS which is 3.6.5E (cat3k_caa-universalk9.SPA.03.06.05.E.152-2.E5.bin) for Cisco 3850 switches.

Thanks & Best regards;

[Peter Paluch]

Hello,

In addition to Ahmed's answer, the 16.x version seems to refer to a so-called Denali version of IOS-XE that has a reworked internal structure and some features added. However, I noted somewhere that 16.2 is soon to be deprecated and replaced by 16.3, so I would personally wait for 16.3 to come.

Check out this presentation - it should be an interesting reading (you may need to register to the Cisco Live website to access the presentation):

http://d2zmdbbm9feqrf.cloudfront.net/2016/usa/pdf/BRKCRS-3300.pdf

Best regrads,
Peter