Data Center Frontiers: Greenfield vs. Brownfield in Cisco Deployments

Alexander Stevenson · ‎05-14-2024

Cisco's Application Centric Infrastructure (ACI), Nexus switches, and Unified Computing System (UCS) are key components of Cisco's Data Center portfolio and provide a comprehensive solution for modern data center infrastructure.

ACI (Application Centric Infrastructure) is a software-defined networking solution that enables application agility and data center automation. ACI provides a policy-driven approach that automates provisioning and managing of resources, allowing for simplified, scalable, and secure data center operations.
Nexus Switches are a range of Cisco switches designed specifically for the data center. They offer high performance, high density, low latency, and power efficiency, and are optimized for a range of data center architectures, including those that utilize ACI for a software-defined approach.
UCS (Unified Computing System) is an integrated data center platform that combines computing hardware (servers), networking, storage access, and virtualization resources into a single cohesive system. UCS simplifies the data center's infrastructure and aims to reduce the total cost of ownership (TCO) and increase scalability.

Together, these technologies are intended to create an integrated and optimized environment for data centers that support automation, management, scalability, and operational efficiency.

In the context of Cisco Data Center technologies, the terms "greenfield" and "brownfield" refer to two different approaches or environments for deploying and integrating new data center infrastructure and technologies.

Greenfield Deployment

A greenfield deployment refers to a scenario where a new data center or network infrastructure is built from scratch. There will be no existing constraints or complications presented by legacy systems because the environment is completely new. This usually happens in a new facility or when a company decides to create a completely separate network for a specific purpose.

Advantages:

Design Freedom: Since there are no pre-existing systems, the design of the data center can be optimized without compromise.
Latest Technologies: The opportunity to deploy the latest technologies, like Cisco ACI for network automation and policy-driven infrastructure, without worrying about compatibility with older systems.
Simplicity: Fewer initial complexities as there are no legacy systems to integrate or migrate.
Efficiency: Potentially more energy-efficient and better-performing systems, as the latest standards and equipment can be used.

Disadvantages:

Cost: Can be expensive as it involves purchasing new equipment and technologies. as well as building new facilities or infrastructure.
Time: It will likely take more time to plan and deploy a new environment from the ground up.
Risk: There may be risks associated with the implementation of new and untested designs or technologies from the organization's perspective.

Brownfield Deployment

A brownfield deployment refers to upgrading or integrating new technologies into an existing data center or network infrastructure. The existing environment may contain legacy systems that need to be considered and worked around.

Advantages:

Cost Savings: It can be more cost-effective to upgrade existing systems rather than replace them entirely.
Leveraging Investments: Organizations can leverage their previous investments in infrastructure and gradually introduce new technologies.
Lower Risk: Incremental upgrades can be less risky because each change can be more carefully planned and tested.
Familiarity: Existing staff may be more familiar with the current environment, which can ease the transition and reduce training requirements.

Disadvantages:

Design Constraints: The design and implementation of new solutions may be limited by the existing infrastructure and compatibility requirements.
Complexity: Integrating new technologies into legacy systems can be complex and challenging, potentially leading to integration issues.
Pace of Innovation: The opportunity for adopting new technologies may be lower due to the need for careful planning and the potential need for step-by-step upgrades.
Operational Disruption: Upgrading a live environment can cause disruptions if not managed properly.

When Cisco ACI, Nexus, and UCS are deployed in a greenfield scenario, it allows for the full utilization of their capabilities without having to worry about legacy constraints. For example, ACI can be deployed to create a fully automated and policy-driven network environment from day one.

In a brownfield scenario, these technologies may need to be integrated with existing networks and systems. For instance, Cisco's ACI can still be introduced into an existing data center by using a network-centric approach to ease the transition from traditional networking to ACI's application-centric model. In the next section, we examine how Cisco Nexus 900 Series Switches can facilitate this transition.

Both greenfield and brownfield projects have their own set of challenges and opportunities, and the choice between them depends on the specific business objectives, budget, and timeline constraints of an organization.

Advantage of Nexus 9000 Series Switches for Brownfield Transition

The Cisco Nexus 9000 Series switches have the unique capability of operating in two distinct modes: NX-OS mode and ACI (Application Centric Infrastructure) mode. This dual-mode functionality plays a significant role in brownfield transitions where existing data center infrastructures are being modernized or integrated with new technologies.

NX-OS Mode:

In NX-OS mode, the Nexus 9000 operates as a traditional network switch running Cisco's Nexus operating system. This mode is used in typical network environments where individual switches are managed and configured independently, often via API.
Organizations with existing Nexus deployments may be running their switches in NX-OS mode, which provides them with a familiar operational model and a wide range of features for network configuration and management.

ACI Mode:

In ACI mode, the Nexus 9000 switches become part of a Cisco ACI fabric and are managed centrally by the Cisco APIC (Application Policy Infrastructure Controller). ACI mode enables a policy-driven infrastructure where the network configuration is abstracted and simplified through the use of application-based policies and profiles. API interaction is done with APIC alone and not with individual devices as with NX-OS mode.
ACI mode is designed for more modern data center architectures that require automation, simplified management, and a more application-centric approach to networking.

When transitioning to ACI in a brownfield deployment, the dual-mode capability of Nexus 9000 switches can be a significant advantage:

Gradual Transition: Organizations can start by deploying Nexus 9000 switches in NX-OS mode to replace older or legacy hardware or to augment their existing network, ensuring compatibility and integration with their current setup. This allows them to transition at their own pace without a complete overhaul.
Training and Familiarization: Network teams can familiarize themselves with the new hardware and its capabilities while still operating in the traditional NX-OS mode. This can reduce the learning curve when eventually moving to ACI mode.
Leveraging Existing Equipment: If an organization already has Nexus 9000 switches running in NX-OS mode, they can repurpose this hardware for ACI by transitioning to ACI mode. This allows them to protect their investment and avoid the need for entirely new hardware.
Testing and Staging: A mixed blue/green environment can be set up where some Nexus 9000 switches are running in NX-OS mode and others in ACI mode, allowing for testing, development, and careful staging of the ACI deployment.
Phased Approach: Organizations can adopt a phased approach to ACI integration, where they initially deploy a small ACI fabric and gradually expand it, migrating workloads from the NX-OS mode switches to the ACI fabric as they become more comfortable with the technology.

The ability of the Nexus 9000 Series to switch between NX-OS and ACI modes provides flexibility for organizations looking to modernize their data centers. It allows them to begin leveraging the benefits of ACI's policy-driven automation and scalability while maintaining continuity of existing operations. This duality is particularly beneficial in brownfield environments, where minimizing disruption and ensuring a smooth transition are critical considerations.

Resources

UCS

UCS: Migrating Brownfield to Greenfield

Cisco Servers - Unified Computing System (UCS)

Experience Data Center Efficiency with Cisco’s Unified Computing System (UCS)

ACI

Cisco Application Centric Infrastructure (ACI)

Migrating Existing Networks to Cisco ACI

Discussion: Cisco ACI Migration Scenario

Nexus

Cisco Nexus 9000 Series switches

Other