Cisco Nexus
By Cisco
Cisco Nexus is a family of network switches from Cisco designed for data center environments, providing the high port density, throughput, and low latency needed to connect racks of servers and storage systems inside a data center fabric.…
Definition
Cisco Nexus is a family of network switches from Cisco designed for data center environments, providing the high port density, throughput, and low latency needed to connect racks of servers and storage systems inside a data center fabric. It runs Cisco's NX-OS operating system, which is distinct from the IOS software used on Cisco's campus, branch switch, and router product lines.
Overview
Data centers need switching infrastructure that can move traffic between thousands of servers with minimal delay and can scale to very high port counts without becoming a bottleneck, a set of requirements distinct from what an office network needs. Cisco built the Nexus line specifically to address this, separating data center switching into its own product family with its own operating system rather than extending its general-purpose switch line. Nexus switches run NX-OS, a modular operating system built to support features data centers rely on, such as virtual port channels that let a server connect redundantly to two physical switches while appearing as a single logical link, and support for overlay networking protocols that let virtual networks span across physical switch boundaries. Different Nexus models are positioned at different layers of a data center fabric, with some models built as high-density spine switches aggregating traffic from many leaf switches, and others built as top-of-rack leaf switches connecting directly to servers, reflecting the spine-leaf architecture common in modern data center design. Within Cisco's own lineup, Nexus is distinct from Catalyst, which targets campus and branch networking rather than data centers, and from Meraki, which prioritizes cloud-based simplicity over the deep configurability data center engineers expect from NX-OS. Outside Cisco, Nexus's primary competitor is Arista Networks, whose EOS-based switches target the same data center fabric role with a different software philosophy built around a single unified operating system across its whole hardware range. Enterprises and cloud providers deploy Nexus switches to build the internal network fabric connecting their servers and storage, relying on NX-OS's data center-specific features to support virtualized workloads and high-availability designs that campus-grade switches are not built to handle. Because NX-OS is a separate software base from Cisco's IOS-family products, network engineers managing both data center and campus Cisco equipment must maintain expertise across two different command syntaxes and feature sets, which adds operational complexity compared to a single unified stack. Nexus hardware also carries the cost and complexity typical of purpose-built data center equipment, generally exceeding campus switch pricing per port. Organizations planning a data center refresh must also account for how a new Nexus generation's feature set interacts with existing overlay network designs and automation scripts, since a hardware upgrade that changes supported NX-OS features can require corresponding updates to automation tooling and monitoring scripts built around the previous switch generation's specific behavior and command output formatting.
Key Features
- NX-OS operating system built specifically for data center switching
- Virtual port channel support for redundant server-to-switch connections
- High-density spine and top-of-rack leaf switch models
- Overlay networking protocol support for virtualized data center fabrics
- High port density and low-latency switching for server-to-server traffic
- Separate software base from Cisco's campus and branch IOS product lines
- Designed for spine-leaf data center network architectures