Fortunately, Cisco thought about it and made available an ACI simulator for people interested by this technology to simulator a whole ACI environment. This simulator includes Cisco APIC instances with real production software, as its native tools (GUI & CLI) use the same APIs that are published for third parties, making it possible to simulate any use case. For instance, you would be able to test an ACI VMM integration, by configuring your simulated ACI environment to an existing vCenter installation, and then controlling your vDS switch and port groups from ACI. Furthermore, the Cisco ACI Simulator allows you to simulate faults and alerts to facilitate testing and demonstrate features.
It’s worth noting though, that the ACI Simulator includes simulated switches, so you cannot validate a data path. You can configure the policies but the data plane will not be active.
In a nutshell, ACI (Application Centric Infrastructure) is an SDN (Software Define Network) solution from Cisco which allows the network admin to configure and manage the entire network fabric from a single point of management, where all Cisco devices in your infrastructure will be configured and managed from one single GUI through a controller named APIC (Application Policy Infrastructure Controller).
