Reference Guide

TeraScale and ExaScale support the range from 0 to 47. The default for ExaScale is 24.
Related
Commands
load-balance (E-Series) — Change the traffic balancing method.
hash-algorithm ecmp
Change the hash algorithm used to distribute traffic flows across an ECMP (equal-cost multipath routing) group.
S4820T
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 FTOS Command Line Reference Guide .
The following is a list of the FTOS 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 various test scenarios,
481