Deployment Guide
hash-algorithm ecmp
Change the hash algorithm used to distribute trac ows across an ECMP (equal-cost multipath routing) group.
Syntax
hash-algorithm ecmp {crc-upper} | {dest-ip} | {lsb}
To return to the default hash algorithm, use the no hash-algorithm ecmp command.
Parameters
crc-upper Uses the upper 32 bits of the key for the hash computation. The default is crc-lower.
dest-ip Uses the destination IP for ECMP hashing. The default is enabled.
lsb Returns the LSB of the key as the hash. The default is crc-lower.
Defaults
• crc-lower
• dest-ip enabled
Command Modes CONFIGURATION
Supported Modes Full–Switch
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
9.2(0.0) Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information The hash value calculated with the hash-algorithm command is unique to the entire chassis. The default
ECMP hash conguration is crc-lower. This command takes the lower 32 bits of the hash key to compute the
egress port and is the “fall-back” conguration if you have not congured anything else.
The dierent hash algorithms are based on the number of ECMP group members and packet values. The default
hash algorithm yields the most balanced results in various test scenarios, but if the default algorithm does not
provide satisfactory distribution of trac, use this command to designate another algorithm.
When a member leaves or is added to the ECMP group, the hash algorithm is recalculated to balance trac across
the members.
hash-algorithm seed
Select the seed value for the ECMP, LAG, and NH hashing algorithm.
Syntax
hash-algorithm seed value [linecard slot] [port-set number]
Parameters
seed value Enter the keyword seed then the seed value. The range is from 0 to 4095.
linecard slot Enter the keyword linecard then the linecard slot number.
port-set number Enter the keywords port-set then the linecard port-pipe number.
Defaults none
Command Modes CONFIGURATION
Equal Cost Multi-Path (ECMP) 461