Center Architectures -repost- ((top)): Nx-os And Cisco Nexus Switching- Next-generation Data

Cisco NX-OS is a modular, Linux-based operating system designed for the Nexus 9000, 7000, 5000, and 3000 series switches to provide high availability in modern data centers. Featuring a multi-process state-sharing architecture, it enables non-disruptive operations like ISSU and supports key technologies including Virtual Device Contexts (VDCs), vPC, and VXLAN-EVPN. For more detailed information on NX-OS features and architecture, visit Cisco NX-OS Data Sheet. Cisco NX-OS Software Data Sheet

  • First-class automation: Ansible modules, Python SDKs, NX-API, REST, gNMI—supports CI/CD and Infrastructure-as-Code workflows.
  • Integration with orchestration: VMware NSX (interop), cloud platforms, container networking via CNI plugins, Kubernetes integrations (CNI solutions using EVPN/VXLAN).
  • ACI vs NX-OS mode: ACI provides policy-driven automation with APIC controller; NX-OS mode favors CLI/SDN-less programmability.

Stateful Process Restart: Automatically restarts failed processes while maintaining current network state. Cisco NX-OS is a modular, Linux-based operating system

  • If you want a low-cost, fully open-source stack with minimal vendor lock-in.
  • Small deployments where advanced features and high port densities are unnecessary.
  • Teams lacking budget for licensing/support or Cisco expertise and training.

How it looks in NX-OS:

  • The Role of NX-OS: In an ACI fabric, the Nexus switches (usually Nexus 9000 series) run a specific version of NX-OS that acts as the agent for the APIC (Application Policy Infrastructure Controller).

Cisco Nexus switches, powered by NX-OS, offer a range of features that make them an ideal choice for next-generation data center architectures. Some of the key features include: Cisco Nexus switches

The Evolution from IOS to NX-OS

To understand the significance of Nexus, one must first understand its predecessor. Cisco’s classic IOS (Internetwork Operating System) was designed for a different era—collision detection on shared media, slower routing lookups, and monolithic control planes. As data centers grew to contain thousands of virtual machines, IOS began to show critical flaws. A single protocol misconfiguration could cause a "control plane storm," overwhelming the switch’s CPU and bringing down vast segments of the network. powered by NX-OS

Virtual Device Contexts (VDCs): The ability to carve a single physical switch into multiple independent logical switches with their own management and data planes. 📖 Current Relevance (2026 Context)