Object-Based Approach to Cisco ACI: The Logic Behind the Application Centric Infrastructure

Fabric Access Policies, Tenants, VRFs, Bridge-Domains, EPGs, and Contracts are basic building-blocks (Objects) of Cisco ACI. This book translates the GUI-based configurations into JSON data-format to make it easier to understand the relationship between objects and how the APIC configuration can be build using REST API calls. Configuration tasks in the Cisco ACI are most often done in a centralized way either by using a built-in GUI in APIC (Application Infrastructure Controller) or REST API Client. Both methods use REST API calls with JSON or XML data formats. By using REST calls we can create a new object, modify an existing one, get information about the object, or delete the object. So how we define an Object? Each object represents an individual setting (policy), a set of settings (policy group), or a set of settings bind to an interface or group of interfaces (profile + selector) as an example. Object, in turn, is created under the class. As an example, objects which define interface settings such as speed and CDP Policy belongs to the infrastructure class. Classes, in turn, are organized by Packages. As an example, classes Tenant, Ctx (VRF), and BD (Bridge Domain) all belong to Fabric Virtualization (fv) Packages. The relationship between classes depends on their location in the Management Information Model (MIM) structure.

Traditional CLI-based box-by-box configuration differs radically from the APIC centralized object-based configuration model. This book explains what happens under the hood of ACI by explaining the relationship between GUI-based configuration results in a JSON data format from the object perspective. Objects are then placed into the MIM tree to illustrate the interdependencies. The first chapter explains the initial ACI installation process. The rest of the book explains how to create a logical overlay network for the application using Web and App servers including filters, and external Layer-2 connection as well as Layer-3 connections using BGP.