Cisco has been at the forefront of developing a suite of standalone tools for data center networking, collectively known as the Day 2 Operations Suite. Recently, Cisco has initiated the integration of these tools into a unified interface called NEXUS Dashboard, providing a consolidated view and shared data repositories for enhanced application correlation. This Learning path is designed specifically for those new to networking or new to the NEXUS Dashboard product. Future learning paths will go into more detail about operating and implementing the NEXUS Dashboard platform.

Cisco ACI is a policy-driven CLOS or Spine/Leaf based switching fabric utilizing layer 3 ECMP routing in the underlay and VXLAN encapsulation in the overlay to transport layer two and layer three traffic East/West across the fabric and North/South in and out of the fabric. ACI consists of the Application Policy Infrastructure Controller (APIC), a centralized controller that manages all aspects of the ACI fabric. The leaf switches are ToR switches that provide connectivity between servers and external networks, and the spine switches are Layer 3 switches that provide ECMP high-bandwidth connectivity between leaf switches. An ACI fabric can be expanded East/West by adding leafs, cabling to the spines, and registering them. ACI was designed to operate as "One Big Switch" (like a chassis-based NEXUS 7K) with the controllers acting like the Supervisors, the spines as fabric modules, and leafs acting as blades. This approach allows us to decouple these elements from the chassis and place them anywhere in the data center. The leafs (blades) can be placed anywhere in the data center, so you are not limited to a chassis. We can take this decoupling one step further and put a leaf in a remote data center (remote leaf), place a spine and leaf fabric extension into a second data center (multi-pod), or a new spine-leaf fabric in a data center (multi-site). Using the NEXUS Dashboard Orchestrator (NDO), we can treat multiple fabrics as one entity from a policy standpoint and manage and perform day two operations from a single pane of glass. The power of ACI allows us to stretch layer two and layer three across multiple fabrics and use a single policy for forwarding traffic in the data center. This Learning Module will guide you through basics and implementation skills.

The Cisco ACI: Tenant & Fabric Connectivity learning path is the second part of our ACI fundamentals training, following the "Cisco ACI Fabric Initialization and Hypervisor Connectivity" path. This path covers two key areas: 1) Fabric Infrastructure configurations, which involve physical fabric setup, including vPCs, VLANs, loop prevention, underlay BGP protocol, etc. 2) Tenant Configurations, defining logical constructs like application profiles, bridge domains, and EPGs. In this Learning Path, students will learn to create Tenants, Application Profiles, Bridge domains, and EPGs, by using objects for connectivity within a physical ACI fabric. They will also discover how to connect Layers 2 and 3 to external networks and explore methods for segmentation using contracts and filters to support both Inter-EPG and Intra-EPG segmentation.

This is part 1 of our ACI fundamentals training, with Part 2, "Cisco ACI: Tenant & Fabric Connectivity," as the next step in the series. Cisco's APIC functions like a switch supervisor, configuring the fabric as if it were a single switch. The Spine/Leaf fabric discovery and self-assembly occur seamlessly, similar to plugging in the supervisor (APIC), fabric module (Spine), and blades(Leafs). This Learning Path delves into ACI's discovery process, fabric construction, and its extension to hypervisors via VMM integration, thereby expanding ACI control to the hypervisors' vSwitch. Part 2 will dive deeper into configurations that are applied to designate ports as access, trunk, or L3 ports.