Hi MUQ_1899_
The APIC uses the Opflex protocol to communicate with the Nexus 9000 switches.
You can read more about Opflex here, and the latest draft standard here.
Opflex is also used by Cisco's AVS and by Microsoft's hyper-v switch - hear MS executive Brad Anderson talk about it here and you can find details about the Opflex extensions for the Open Virtual Switch (OVswitch) here.
HTH
CW
RedNectar aka Chris Welsh.
Forum Tips: 1. Paste images inline - don't attach. 2. Always mark helpful and correct answers, it helps others find what they need.