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enhanced-hash-key (EX)

Syntax (EX Series)

Syntax (QFX5000 Series Switches)

Syntax (QFX10000 Series Switches)

Syntax (SRX5000 Series Routers))

Syntax (Junos OS Evolved)

Syntax Junos OS Evolved (QFX5220 and QFX5130)

Hierarchy Level

Junos OS Evolved uses the set command instead of edit.

Description

Configure the hashing key used to hash link aggregation group (LAG) and equal-cost multipath (ECMP) traffic, or enable adaptive load balancing (ALB) in a Virtual Chassis Fabric (VCF).

Note:

Starting in Junos OS Release 14.1X53-D46, 15.1R7, 16.1R6, 17.1R3, 17.2R2, 17.3R2, and 17.4R1, the ALB feature is deprecated. If fabric-load-balance is enabled in the configuration for a VCF, delete the configuration item upon upgrading Junos OS.

The hashing algorithm is used to make traffic-forwarding decisions for traffic entering a LAG bundle or for traffic exiting a switch when ECMP is enabled.

For LAG bundles, the hashing algorithm determines how traffic entering a LAG bundle is placed onto the bundle’s member links. The hashing algorithm tries to manage bandwidth by evenly load-balancing all incoming traffic across the member links in the bundle.

When ECMP is enabled, the hashing algorithm determines how incoming traffic is forwarded to the next-hop device.

QFX10000 Series switches
  • On QFX10000 Series switches, you can configure the hash seed for load balancing. By default, the QFX10000 Series switches use the system MAC address to generate a hash seed value. You can configure the hash seed value using the hash-seed statement at the [edit forwarding-options enhanced-hash-key] hierarchy level. Set a value between 0 and 4294967295. If you do not configure a hash seed value, the system generates a hash seed value based on the system MAC address.

  • Starting in Junos OS Release 18.4R1, symmetric hashing is supported on the QFX10000 Series switches. You configure the no-incoming-port option under the [edit forwarding-options enhanced-hash-key] hierarchy. By default, Destination IP (DIP), SIP, Layer 4 source and destination ports, and the incoming port are used for hashing. You can only configure symmetric hashing at the global level.

QFX5000 Series switches
Note:

On QFX5000 Series switches, multicast packets gets duplicated or dropped when vlan-id is included in the enhanced-hash-key configuration. Hence, while configuring enhanced-hash-key, you must configure layer2-payload and layer2-header options without configuring vlan-id. This behavior is only seen in multicast traffic.

  • Starting in Junos OS Release 19.4R1, the dynamic load balancing on ECMP is supported on QFX5120-32C and QFX5120-48Y switches. You can configure the ecmp-dlb option under the [edit forwarding-options enhanced-hash-key] hierarchy. Refer Dynamic Load Balancing for more details.

  • To enable symmetric hashing on the QFX5000 line of switches, configure the symmetric-hash option.

Enhanced hash key is supported on SRX5000 routers by implementing control path for for the configured setting to reach the services processing card (SPC2) and SPC3. You configure the session-id option to enable the control path for the configured setting to reach the service processing unit (SPU).

The remaining statements are explained separately. See CLI Explorer.

Required Privilege Level

interface—To view this statement in the configuration.

interface-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Release 13.2X51-D15.

The fabric-load-balance statement introduced in Junos OS Release 14.1X53-D10.

The fabric-load-balance statement deprecated starting in Junos OS Releases 14.1X53-D46, 15.1R7, 16.1R6, 17.1R3, 17.2R2, 17.3R2, and 17.4R1.

The hash-seed statement introduced in Junos OS Release 15.1X53-D30.

The ecmp-dlb statement introduced in Junos OS Release 19.4R1 for QFX5120-32C and QFX5120-48Y switches.

Option symmetric-hash introduced in Junos OS Release 20.4R1.

Statement introduced in Junos OS Evolved Release 21.3R1.

The ecmp-dlb statement is introduced in Junos OS Release 23.2R1 for EX4400-24T, EX4400-24X, and EX-4400-48F switches.