Administrator Guide

hash-algorithm ecmp
Change the hash algorithm used to distribute traffic flows across an ECMP (equal-cost multipath routing)
group.
Z9000
Term heading Description heading
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
Command History
This guide is platform-specific. For command information about other platforms,
refer to the relevant Dell Networking OS Command Line Reference Guide.
The following is a list of the Dell Networking OS version history for this command.
Version
8.3.19.0
Introduced on the S4820T.
Version 8.3.11.1 Introduced on the Z9000.
Version 8.3.7.0 Introduced on the S4810.
Version 8.1.1.0 Introduced on the E-Series ExaScale.
Version 7.6.1.0 Introduced on the S-Series.
Version 7.5.1.0 Introduced on the C-Series.
Usage Information The hash value calculated with the hash-algorithm command is unique to the
entire chassis. The default ECMP hash configuration is crc-lower. This command
takes the lower 32 bits of the hash key to compute the egress port and is the “fall-
back” configuration if you have not configured anything else.
The different hash algorithms are based on the number of ECMP group members
and packet values. The default hash algorithm yields the most balanced results in
550
Equal Cost Multi-Path (ECMP)