astructure. Development and Production are two different VRFs as a part of the customer A environment. There is a Development bridge domain under VRF A and has a single subnet A. There is also a Production BD under VRF B which has two subnets part of the same bridge domain under the same VRF. Customer B is Tenant B in ACI and has only one VRF C which is application VRF. There are two applications BD with only a single subnet. Cisco ACI enables to integrate physical and virtual workloads in highly programmable and multi- hypervisor environment and multi-Tenant environment. It behaves as a single big switch with spines as the fabric modules and leafs as the line cards of a single big modular chassis switch. Adding more leaf is like adding more line cards for end points connectivity and adding more spines is like adding more backplane bandwidth to the switch. ACI Fabric Inside ACI fabric has IS-IS as the routing protocol which helps to advertise VTEP IDs and loopbacks to create tunnels from every leaf switch to all other nodes within the fabric. Infrastructure VRF is used by the management network for in-band communication between Controller APIC and Switches. Out of band management OOB is through the management ports to access the APIC cluster. Figure 6. CUSTOMER A (TENANT A) CUSTOMER B (TENANT B) DEVELOPMENT (VRFA) PRODUCTION (VRFB) APPLICATION SERVIC (VRFC) PRODUCTION DEVELOPMENT APPLICATION 1 Bridge Domain APPLICATION 2 Bridge Domain Bridge Domain SUBNET B Bridge Domain SUBNET A SUBNET D SUBNET E SUBNET C Downloaded: 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 SDN Practical Orientation ACI REST APIs Representational state transfer (REST) architecture is based on a set of principles that supports cloud platforms which is simple, fast & light weight approach. ACI API is REST based. As APIC is designed for the programmability, It accepts & returns HTTP/HTTPS messages that contain JSON - JavaScript Object Notation or XML- Extensible Markup Language documents. Any programming language c