Why APIC in ACI specifically needs Nexus 9k to run?

[DOUGMALLOCH1]

Hi guys,

Just to straighten my understanding of APIC and APIC-EM within the ACI initiative.

From the various Cisco and general resources, I am under the impression that the APIC's and APIC-EM's southbound leverages OpenFlow and OnePK to talk to a wide range of devices.

If so, ACI southbound should be able to a select range of legacy devices.

Since the APIC hardware already houses the code of the "brain", including northbound REST and southbound protocols,

• Why does APIC hardware specifically need Nexus 9k spines and leaves to run?
• What is APIC's dependency on Nexus 9k?

Many thanks

[dpita · Accepted solution]

Hello,

A very simple answer to both of your questions is that the n9k is the only Cisco switch that understands the policy model that the APIC uses, this is in part due to the firmware image that the switches run which is very different from standard NX-OS. Also, the Cisco Application Leaf Engine(proprietary ASIC) in the GEM on the leaf switches understands and makes forwarding decisions based on that policy. 

Thanks for using ACI support forums! hope this helps.