ACI provides cross-physical and cross-virtual resource unified policy definition and application, in addition to bare-metal server installations. This can be achieved automatically through the use of APIs or an intuitive graphical user interface. By selecting the latter option, it is possible to integrate ACI into the existing DevOps processes.
How does ACI function?
ACI (Application Centric Infrastructure) is a network architecture for data centres that enables the deployment and administration of applications in a more flexible and efficient manner. The ability to administer both physical and virtual networks from a single point of contact facilitates enhanced transparency and simplifies the administration of intricate networks.
The implementation of ACI improves the agility and efficacy of the data centre by automating manual processes that are susceptible to error in various respects. To illustrate, ACI is capable of accurately identifying errors in the configuration of any given application. These errors can then be automatically rectified through the deployment of the appropriate and updated application on the infrastructure.
Additionally, the network can autonomously adapt to ensure that the necessary resources are provided at the appropriate time and location. Furthermore, it offers a significantly augmented capability for security and compliance. It is outfitted with remarkable attributes, including intrusion detection/prevention systems and built-in firewalls, which safeguard the Data Center's assets from malicious attacks.
ACI can be defined as a network architecture for data centres that facilitates the deployment and administration of applications in a more adaptable and effective manner. ACI can aid in enhancing the agility, effectiveness, security, and compliance of a data centre.
ACI offers numerous advantages, some of which are detailed below.
The Cisco ACI Advantages
The following are several noteworthy advantages of utilising ACI:
The application-driven policy model streamlines the automation process.
The emphasis should be on applications and their velocity. Thus, the Data Centre is capable of managing any workload at any time.
• Integration Capabilities—Protection of investments through integration with the current fabric infrastructure, such as the Nexus 7000
• Virtualization
• Networking containers
• Orchestration
• Networking in the public cloud
• Scalable performance and hardware multitenancy
• Open software flexibility for DevOps teams and ecosystem partner integration
• Centralised visibility with real-time application health monitoring
ACI Architecture by Cisco
By allowing you to construct the network of your data centre in accordance with the specifications of your applications, Cisco ACI infrastructure is referred to as "application centric." It employs a centralised policy model to streamline and automate the configuration, deployment, and management of the network. This enables enhanced flexibility, scalability, and manageability due to the decoupling mechanism between the network control plane and the data forwarding plane facilitated by its architecture.
ACI Components from Cisco
The fundamental components of the ACI architecture are the Cisco Nexus 9000 series switches, the APIC, and the ANP, which comprise the Cisco ACI fabric with a two-tier spine-leaf topology.
Three fundamental elements comprise the Cisco ACI architecture:
1. Application Policy Infrastructure Controller (APIC) – The centre of the ACI architecture, the Application Policy Infrastructure Controller (APIC) is an acronym for Application Policy Infrastructure Controller. A centralised software controller that is intended to enforce policies, monitor health, and facilitate programmability (automation).
Maintenance of switch firmware and fabric activation fall under the purview of APIC.
• Establishing a connection between network programming and application policies.
• Increasing efficiency.
• Sustaining any application in any location.
• The consolidation of physical and virtual environment operations.
• Operating and managing a multitenant, scalable Cisco ACI fabric.
Additionally, unlike SDN controllers, Cisco APIC does not manually manipulate the data path. Programmatically programming the leaf switches to forward traffic in accordance with the defined policies, it centralised the policy definition.
Moreover, since the APIC is entirely eliminated from the data path, the fabric can continue to forward traffic even if communication with it is lost in a network. Ensuring consistent availability is a key feature of ACI.
Within the ACI fabric, the APIC is situated between the ANP and the ACI-enabled network infrastructure. A northbound API is made available via XML and JSON, and it is utilised to administer the fabric via a command-line interface (CLI) and graphical user interface (GUI).
Multiple configuration methods are supported, including a command line interface, REST API, Python API, Bash scripting, and GUI. Additionally, APIC offers an open-source southbound API that enables policy control of supplied devices to be implemented by third-party network service providers.
2. AnNP (Application Network Profile)
In contrast to the APIC, the Application Network Profile (ANP) comprises endpoint groups (EPG), their respective connections, and the corresponding policies that delineate said connections. EPG is a logical aggregation of endpoints that are representative of a service set or application tier that requires a comparable policy.
All application components and their interdependencies on the application fabric are logically represented by ANP. Their fundamental purpose is to facilitate logical modelling that corresponds to the manner in which applications are developed and implemented. Furthermore, the system handles the configuration, policy enforcement, and connectivity, eliminating the need for manual intervention by an administrator.
The procedures necessary to establish an Application Network Profile.
• Establishing policies that define connectivity with keywords including Permit, Deny, Log, Mark, Redirect, and Copy
• Require policy consistency and reusability when drafting contracts for services that frequently communicate with multiple EPGs.
3. Cisco Nexus Portfolio: Cisco ACI Fabric
Cisco's expansion of its Nexus portfolio is evident from the recent introduction of Cisco Nexus 9000 Series Switches, which are designed for utilisation in both conventional and Cisco ACI data centres. These switches manage the physical and virtual network infrastructure in conjunction with an APIC and provide an application-aware switching fabric.
Their fixed and modular 1/10/40 Gigabit Ethernet switch configurations place them in high demand. Furthermore, their design facilitates operation in either Cisco NX-OS mode or Cisco ACI mode.
Compatibility and consistency with the existing Cisco Nexus switches are provided by both modes, enabling data centres to fully leverage the infrastructure automation capabilities and application policy-based services of Cisco ACI.
The fundamental ACI component, Cisco Nexus switches are endowed with these capabilities. By leveraging this technology, they afford clients investment security and facilitate the transition to Cisco ACI via a software update.
Thus, these ACI components render this technology accessible to clients of any size and an ideal match for the switching of next-generation data centres.
To conclude, In essence, the Cisco ACI Architecture is a robust solution that streamlines network administration, fortifies security measures, and affords organisations adaptability and expandability. Policy-driven model, APIC, and leaf and spine network fabrics are essential Cisco ACI components that enable granular policy enforcement, low-latency connectivity, and centralised control.
Organisations can enhance overall network performance, consolidate operations, and reduce complexity by implementing Cisco ACI. The flexibility and characteristics of the architecture render it a highly suitable option for organisations in search of improved scalability, security, and performance. The adoption of Cisco ACI enables organisations to regain authority, respond to evolving requirements, and foster inventive practices within their network infrastructure.
In order to meet the talent requirement, a data centre specialist must have completed Cisco Nexus 9000 training in order to deploy and manage Cisco Nexus® 9000 Series Switches in NX-OS and ACI mode.
