Resilient Hashing

Resilient Hashing is a hardware-based capability that minimizes the remapping of flows to aggregator member ports during aggregator member changes.

In conventional hashing, physical links are used to form fat logical pipes. The static hash scheme associates a flow with a physical link. When a link fails, even flows that did not originally flow through the failed link may be assigned to a new link. This reassignment may temporarily result in out-of-order packet deliver even for the flows that were not using the failed link. In contrast, a resilient hashing scheme associates flows with physical ports. When a link fails, only the affected flows are redistributed uniformly across the remaining good physical links. Flows using functioning links remain unaffected and are not reassigned to new links.

Supported Platforms

Summit X770 and X670-G2, and on SummitStacks when at least one of the supported switches is included in the stack.

On SummitStacks, configuration of resilient hashing is not allowed unless at least one node in the stack supports resilient hashing. In a stack where one or more nodes support resilient hashing and one or more nodes do not support resilient hashing, resilient hashing is only in effect for flows received on ports on nodes where resilient hashing is supported by the hardware.


  • Resilient hashing is available only on LAGs configured to use the “custom” distribution algorithm.
  • Resilient Hashing applies only to the distribution of known unicast traffic.
  • Traffic originating or forwarded by the system CPU is not distributed using Resilient Hashing.

New CLI Commands

configure sharing master_port resilient-hashing [on | off]

Changed CLI Commands

Changes are underlined.

enable sharing master_port grouping member_port_list {algorithm [address-based {L2 | L3 | L3_L4 | custom} | port-based]} {distribution-mode [all | local-slot | port-lists]} {resilient-hashing [on | off]} {lacp | health-check}