Cisco ACI APIC Upgrade

[islam.kamal]

Dear experts,

We have any upgrade for Cisco APICs, we verified all pre-requisites and we are fully fit to do upgrade without any issue. Our inquiry during the ACI APIC upgrade, is there any expected downtime or interruption. Appreciate your feedback. 

[Sergiu.Daniluk]

When upgrading the APIC cluster, there is no downtime or impact on user traffic. This is because the APIC is just a controller and there is no user traffic flow passing through APIC. Taking this idea further, even if all APICs from cluster are going down at the same time (reload for example) and the fabric nodes remains up, the user traffic will not be impacted.

Stay safe,

Sergiu

[RedNectar]

Hi @islam.kamal ,

As @Sergiu.Daniluk says, there will be no impact on traffic during an APIC upgrade.

BUT it is common to upgrade the ACI switches immediately after upgrading the APIC.  During a switch upgrade, each switch will reboot.  Therefore, best practices is to have all devices dual connected via two DIFFERENT switches, typically one odd numbered switch and one even numbered switch.

Then, you configure the upgrade process to upgrade the Odd numbered switches first, and only when the network is stable again, upgrade the even numbered switches.

That way you maximise the chance of a smooth upgrade, but like all these things, there is always the possibility that something will not work as planned, so we always recommend conducting upgrades during a maintenance window.