What would be the correct Approach to Upgrade Fabric switches in DNAC

[Pankaj.bandewar1]

What would be the correct Approach to Upgrade Fabric switches in DNAC ..? 

Like start upgrade from where 

option 1 -  Core > Distribution > Access 

Option 2 - Access > Distribution > Core 

we have 300+ sites running Core as 9500 / 9300 and Access Switches as 9200 switches running role of FIAB and eWLC ( Fabric Wireless ) .

I had a bad experience in upgrading Core 1st i lost connectivity to all my access switches on site.

We are planning to Upgrade to 17.09.04a from 17.6.5

Suggestions Appreciated !  

@DNAC @switches_upgrade_sequence 

[Ruben Cocheno]

@Pankaj.bandewar1 

I always go with access first and leave running for some time, before moving to Dis and Core finally.

[balaji.bandi]

we have 300+ sites running Core as 9500 / 9300 and Access Switches as 9200 switches running role of FIAB and eWLC ( Fabric Wireless ) .

in this case i upgrade Access switches - looking at WLC compatable matrix with AP.

Monitor the network stablility - gradually increase the number of upgrades.

Same Distribution one side Monitor

Finally Core upgrade and monitor

In case required DNAC to upgrade to latest version 2.3.5 is good option.

[Pankaj.bandewar1]

thanks for the suggestion

is there any Cisco recommendation available , any link , as our Management people love only official documentation 

[balaji.bandi]

I do not believe you find any document around cisco site what device to upgrade first - its all approach and tested methods and learning lessons from past mistake in different upgrade methods.

i can only guide you how to upgrade some videos using DNAC :

https://www.youtube.com/watch?v=kjkCByvIXVI

https://www.youtube.com/watch?v=oDrCIAR8Scg