Cisco's Application Centric Infrastructure (ACI) framework is an integrated solution of the Nexus 9000 switching/routing hardware and the Application Policy Infrastructure Controller (APIC) software. The solution is similar to VMware NSX and Big Switch Networks' Big Cloud Fabric.

In Chapter 7, VMware NSX, we discussed the differences between NSX and ACI. While there are many similarities, such as the use of an overlay network, VXLAN, and other technologies, ACI is still a hardware-focused system, whereas NSX is a software-based system. From a technical perspective, NSX can be integrated into ACI and provides complementary features.

ACI was created at Insieme Networks, a spin-in company that Cisco originally funded and then acquired. ACI is a straightforward concept where policies are applied to end users/groups instead of interfaces; these policies are called Endpoint Groups (EPGs).

At the 10,000 foot level, an ACI network looks just like a normal leaf-spine network. As...