Cisco Cisco Prime Network Services Controller Adaptor for DFA White Paper

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Operation simplicity: Cisco Data Center Network Manager (DCNM) 7.0 provides centralized fabric

management across physical and virtual software deployments, including auto deployment, integrated

fabric access, topology views, monitoring, and health checks. Open APIs allow better integration with

orchestration and automation tools in addition to cloud platforms.

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Greater agility: Network automation and provisioning accelerate application delivery with greater VM

mobility and smaller failure domains.

Figure 1. Cisco Dynamic Fabric Automation Architecture

Cisco DFA is generally topology independent. Cisco believes that most virtualized data centers will adopt a spine-

and-leaf architecture consisting of leaf nodes at the edge of the fabric and spine nodes at the core of the fabric.

This design helps ensure that any application nodes are at most only two hops from each other or from IP-based

storage, providing predictable latency for all east-west traffic. Data does not travel between spine switches and

can predictably move from leaf to spine to leaf.

The leaf nodes represent the physical network edge, connecting to the application servers and service nodes. This

edge presents Layer 2, Layer 3, and network services to any physical or virtual applications connected to it. Cisco

DFA advancements include enhanced forwarding, in which IP addresses are used regardless of whether the

communication is within or between traditional Layer 2 subnets. This feature introduces several optimizations and

simplifications, including the elimination of a first-hop redundancy protocol, the use of small MAC address tables,

and optimal forwarding for all unicast frames.

Cisco DFA is designed to support multiple encapsulation or tunneling protocols for multitenancy and path

isolation, and to support classic bridging behavior for non-IP software deployments that rely on flooding for proper

functioning. The initial encapsulation protocol will be based on Cisco FabricPath.

Connectivity from the Cisco DFA to external networks (which traditionally would occur in the Layer 3 core switch)

is now through border leaf nodes. In the spine-and-leaf topology, the core switch layer is folded into border leaf

nodes that act as gateways to external networks and provide the Layer 3 routing support that the efficient spine

nodes push down to the leaf nodes.

Cisco DFA provides an optimal fabric for both physical and virtual software deployments simultaneously. The

connectivity of virtual and physical endpoints is built into the Layer 3 boundary distributed across the network (at

each leaf). This design eliminates the need for specific virtual network and physical network gateways, which can

be bottlenecks and reduce scalability. Compared to a virtual overlay network, Cisco DFA offers more efficient

traffic forwarding alternatives, with greater visibility and control of the physical infrastructure. The resulting fabric

design is free from any dependencies on the hypervisor infrastructure or cloud orchestration software.