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RETIRED - Cumulus Linux 2.5 What's New? (Overview)


This document introduces major new features and enhancements supported under Cumulus Linux 2.5. A companion Cumulus Linux 2.5.0 presentation is also available.

Cumulus Linux 2.5.0 continues to enable the fast-paced world of modern data centers, making it easier for organizations of all sizes to adopt modern networking. In particular, Cumulus Linux 2.5.0 brings:

  • Validated design guides for virtualization, orchestration and big data solutions
  • Choice of data center architectures from among Layer 2, Layer 3, and overlay networks

Cumulus Linux 2.5.1 supports new platforms, in particular, the first 10GBASE-T platform on the Hardware Compatibility List.

Cumulus Linux 2.5.2 adds two new features: resilient hashing (for ECMP link group failures — see below) and jdoo (which replaces monit for monitoring system hardware).

Validated Design Guides

The validated design guides are a great starting point for customer deployments and include detailed, step-by-step procedures.

Validated design guides are available for:

For more information on specific solutions, check the Cumulus Networks Solutions website. 

Choice of Data Center Architectures

Cumulus Linux 2.5.0 continues to strengthen existing IP fabric and overlay architectures and introduces robust active-active Layer 2 architectures for simple transition to modern data center management.

In particular, this release introduces active-active Layer 2 configurations with MLAG support, Layer 2 scale with VLAN-aware bridges, and operational efficiencies with ifupdown2 interface configuration enhancements.




Active-active Layer 2 solution for capacity and redundancy. Bonding provides multipathing, leveraging LACP. MLAG provides a simple migration path to modern data center tooling for existing Layer 2 solutions.

multi-Chassis Link Aggregation Group (CLAG) is the Cumulus Networks implementation of MLAG and leverages the clagd daemon and associated commands.

VLAN Scale

New 802.1Q Linux bridge driver supports one bridge for all VLANs with a single instance of spanning tree (STP, RSTP). This new driver enables VLAN scale (tested to 2000 concurrent VLANs).

This bridge driver is also sometimes referred to as a VLAN-aware bridge. Both the original (per-VLAN) and new bridge driver (VLAN-aware) can coexist. A mixed mode is recommended for migration only.

VRR Enhancements

Virtual Router Redundancy now supports active-active configurations and is enhanced to work with MLAG.

Interface Configuration Enhancements: ifupdown2

Scalable and simplified interface configuration for networking devices.

LACP Bypass

Fallback mechanism for LACP for scenarios such as PXE boot.

Routing Enhancements

IP fabrics are the best way to scale a network via leaf-spines architectures. Cumulus Networks continues to enhance routing functions with Cumulus Linux 2.5.0.

Routing enhancements include scale (update-groups, large number of peers), BGP dynamic neighbors, latest Quagga version (v0.99.23.1).

QoS Enhancements

Enhancements include link PAUSE, a DoS control option, and a store-and-forward configuration option.

DoS control options enable additional checks in hardware to prevent errors/DoS with security checks. These are disabled by default in CL2.5.0.

Resilient ECMP Hashing

Resilient hashing ensures that when a member in an ECMP link group fails, flows on that link are moved to the unaffected links in the group. Existing flows on unaffected links do not move. This fixes the problem of moving flows from unaffected links that can lead to issues.

jdoo jdoo replaces monit, for monitoring hardware. jdoo forks monit version 5.2.5.

Important! Please read the release notes for the steps to upgrade Cumulus Linux to version 2.5.2.


New Platforms

Cumulus Linux 2.5.1 adds support for key new platforms on the HCL:

  • Dell S4048-ON (48x 10G-SFP+ and 6x40G-QSFP+): This platform allows a complete Trident II-based leaf-spine topology with 10GE ports optimized for the leaf, and 40GE ports optimized for the spine. It also minimizes oversubscription with 50% more 40GE uplink ports.
  • QuantaMesh BMS T3048-LY9 (48x 10GBASE-T and 6x 40G-QSFP+): This platform is the first 10GBASE-T platform on our HCL and reflects on the versatility of an open network OS. 10GBASE-T helps in the migration from 1G to 10G since the same 1GBASE-T standard/structured RJ-45 cables can now be reused for 10GBASE-T at distances of up to 100m.
  • QuantaMesh BMS T5032-LY6 with x86 CPU (32x 40G-QSFP+): This platform allows for a complete Trident-II and x86 based leaf-spine topology, with the T3048-LY8 platform optimized for the leaf, and the T5032-LY6 platform optimized for the spine.

For more information on specific features, check the release notes and the Cumulus Linux datasheet, as well as the Cumulus Linux 2.5 What's New and Different (Technical) presentation.


This support portal has moved

Cumulus Networks is now part of the NVIDIA Networking Business Unit! The NVIDIA Cumulus Global Support Services (GSS) team has merged its operations with the NVIDIA Mellanox support services team.

You can access NVIDIA Cumulus support content from the Mellanox support portal.

You open and update new cases on the Mellanox support portal. Any previous cases that have been closed have been migrated to the Mellanox support portal.

Cases that are still open on the Cumulus portal will continue to be managed on the Cumulus portal. Once these cases close, they will be moved to the Mellanox support portal.

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