Cumulus Linux

The first, true Linux Operating System for data center networking

Cumulus Networks is transforming networking with the industry's first, full-featured Linux operating system for networking hardware.

Cumulus Linux is unleashing the power of Open Networking with a network operating system that runs on top of industry standard networking hardware. By providing a software-only solution, Cumulus Linux is enabling disaggregation of data center switches akin to the x86 server hardware/software disaggregation. Data-center networking is rapidly standardizing on merchant silicon and with Cumulus Linux, - the first, true Linux OS for data-center networking – networking is adopting the lingua franca of the data-center.

Because, it’s just Linux, Cumulus Linux provides the ultimate flexibility for modern data center networking designs and operations, enabling the best of breed hardware and solutions ecosystem with a standard operating system. Customers are able to leverage standard server automation & monitoring software and innovate rapidly with custom, open-source or commercial tools providing a modern alternative to proprietary vendor-locked stacks that constrain IT innovation. With 7 open-hardware partners, 80+ solution partners and well over 1 Million switch ports worldwide; Cumulus Networks powers data-centers ranging from small businesses and universities to enterprises and some of the world's largest cloud providers.

Why Cumulus Linux?

Cumulus Linux enables faster, easier and more affordable networks. With Cumulus Linux, your data center network is:


Choice of Hardware, Choice of software, Linux community and ecosystem, Customization, no vendor lock-in


Scale, Automation, Risk Management, Tools & Open Source


Affordable capacity, Substantial CAPEX and OPEX savings

Linux Distribution

Cumulus Linux is Linux. It is a networking focused Debian distribution. Check out our brief overview guide and latest data-sheet to learn more.

Broad Hardware Ecosystem

Cumulus Linux accelerates robust networking functions at wire-rate on a variety of hardware platforms. Cumulus Networks certifies Cumulus Linux operations for all products on the Hardware Compatibility List (HCL)

Robust Solutions Ecosystem

Cumulus Linux is a platform for applications allowing you to choose from thousands of existing linux applications or developing your own. We partner with the leading best-of-the-breed vendors to provide a variety of solutions for your Big Data, Openstack, VMware and other environments.

Cumulus Linux Features

Functionality Description Documentation
Operating System Install & Upgrade

Server-style upgrade/patching across minor releases, server-style process restart/termination.

Support for zero touch OS installation using ONIE loaded on industry standard switches.

View Docs

Linux is the API — Any language supported in Linux today, including scripting with Bash, Perl, Python, Ruby.

Hardware Management

The switch hardware abstraction layer accelerates Linux kernel networking constructs in hardware including the routing table, ARP table, bridge FDB, IP/EBtables, bonds, VLANs, VXLAN bridges.

Hardware management also includes jumbo frames support and environmental management.

Layer 3 Features

Enhanced Quagga IPv4/v6 routing suite including OSPFv2, OSPFv3, BGPv4/v6, Equal-Cost Multi-Path (ECMP).

ECMP Resilient Hashing for IPv4 and IPv6 traffic.

Bidirectional Forwarding Detection (BFD) across all platform & interface types, IPv4 and IPv6, BGP and OSPF, VXLAN.

View Docs
Layer 2 Features

Bridge management with STP (IEEE 802.1d), RSTP (IEEE 802.1w), PVRST, PVST, bridge assurance, BPDU guard, BPDU filter.

VLANs, VLAN trunks (IEEE 802.1q), LACP (IEEE 802.3ad), LACP bypass, unicast/broadcast storm control, LLDP, CDP, IPv6 neighbor discovery, IPV6 route advertisement.

MLAG (clagd daemon).

IGMPv2/v3 snooping, MLDv1/v2 snooping.

Virtual Router Redundancy (VRR - Active-active first hop redundancy protocol).

View Docs
Network Virtualization*

VXLAN Support

L2 Gateway integration with VMware NSX

VXLAN Head End Replication

VXLAN Active-Active bridging with MLAG

Controller-less Network Virtualization with LNV

View Docs

Native Linux management tools such as OpenSSH, SCP, FTPS.

Automated install and provisioning: zero touch install and zero touch provisioning.

Management VRF

DHCP, v4/v6 DHCP relays.

Authentication with LDAP, authorization with sudo NTP.

Interface configuration management (ifupdown2).

Advanced management/orchestration through third party add-on packages.

Monitoring & Troubleshooting

Traditional monitoring with SNMPv2 and network specific MIBs, hardware monitoring via watchdog, analytics with SPAN, ERSPAN, ACL-based counters, DOM optics data, thermal sensors, real time queue-depth and buffer utilization reporting.

Troubleshooting with dnsutils, syslog, reachability tools, hardware inventory, log files, server-style filesystem, and merchant silicon specific commands.

Advanced troubleshooting and ease of use with Prescriptive Topology Manager.

View Docs

Access control lists (ACLs) L2-L4 classification through IP/EPtables, CPU protection through hardware enforced ACL-based rate limiting , DoS control.

View Docs


Classification based on Class of Service (CoS) (IEEE 802.1p) or DSCP (queuing, scheduling (DWRR and Strict Priority), buffer allocation)*.

Ingress ACL-based classification/policing.

View Docs

*Check the appropriate hardware guide for platform-specific support.

Cumulus Linux Architecture

The modern data center is the supercomputer re-invented. Some call it warehouse computing for the sheer scale of the systems. The system consists of fungible compute and storage nodes connected by a high capacity network that is quickly repurposable to the demands of the clustered applications running on them. The glue that allows this to happen is an open, extensible and stable operating system. In the data center, on the compute side that operating system today is Linux.

Compared to the speed, flexibility and manageability of the compute nodes, the network is a veritable dinosaur. It is expensive, hard to manage, slow and proprietary. We want to change that. Cumulus Networks has created the first true, full-featured Linux OS for networking hardware – allowing data centers to break free from proprietary, vertically integrated networking gear.

For Linux to be a network operating system, it has to be responsible for not just the hardware resources but also the structures necessary for networking: route tables, ARP tables, ACLs, interface management, and a whole host of other system information such as power, fans and sensors. In such a world all applications interact with the operating system and its abstractions only, while the operating system manages the devices through device drivers.

It is this criterion which makes Cumulus Linux, Linux. Unlike many industry competitors, we are NOT a Linux-based operating system, we ARE Linux. We offer the entirety of the Linux experience, as you understand it. The front panel ports of the switching fabric appear to the Linux kernel as if they are standard NICs. In other words, we accelerate the data path using the switching silicon while preserving the control and management abstractions of standard Linux. The simplicity and elegance of this model is clear when you consider the integration effort required to run well known networking applications as well as enabling new applications.

For example, control protocols such as routing protocols, spanning tree and LLDP are standard Linux user space applications that operate on native Linux constructs for routing and interface management. Some customers are using their own custom-built routing protocol suite.

As another example, networking and server management can be unified under a common tool chain. You can now use the well regarded and sophisticated tools such as puppet, chef, and CFEngine to configure networking equipment. Furthermore, customers with their own native automation tools can easily integrate with Cumulus Linux because we preserve the management abstractions of standard Linux.

Similarly, on the monitoring side of things, you can use a diverse set of tools such as collectd and Ganglia. Obviously, you can still use traditional network monitoring tools such as SNMP. Since the elements being monitored are always exposed via sysfs or procfs, the channels available for gathering and sending information are not restricted to the usual suspects. Scripts can grab all kinds of raw data and trivially send it for remote analysis without requiring proprietary libraries to be ported.

Finally, since Cumulus Linux is Linux, customers can write applications to run directly on our switches and implement any software agent that they desire. For example, we developed agents for well known network orchestration tools such as Open Stack and VMware NSX with the same ease and agility as developing them on a Linux server. In the case of the VMware NSX integration, our team simply worked very closely with the Linux community and VMware to translate the NSX schema into existing Linux kernel VXLAN data structures. This ease of integration enables the overall experience of interacting with our systems customizable in each deployment.

To summarize, Linux is a natural fit as the network operating system for the data center. With Cumulus Linux, we provide an open, mature, flexible, and easy to manage network operating system for modern data center networks. With Cumulus Linux, we are bringing the Linux Revolution to Networking.

View Requirements of Open Networking

Open Networking requires a combination of bare metal hardware
and a compatible networking operating system.


Cumulus Linux Network OS

Cumulus Linux is a Linux network operating system that runs on top of industry standard networking hardware.


View compatible hardware