Dell Force10 Z9000 FTOS Command Line Reference Guide for the Z9000 System FTOS - Page 612

NOTE: You cannot separate LAG and ECMP, but you can use different algorithms across chassis with the same d. If LAG member ports span multiple port-pipes and line cards, set the d to the same value on each port-pipe to achieve deterministic behavior. NOTE: If the hash algorithm configuration is removed, Hash d does not go to the original factory default setting. hash-algorithm ecmp Change the hash algorithm used to distribute traffic flows across an ECMP (equal-cost multipath routing) group. C-Series, E-Series, S-Series, Z-Series Term heading Syntax Parameters Description heading hash-algorithm ecmp {crc-upper} | {dest-ip} | {lsb} To return to the default hash algorithm, use the no hash-algorithm ecmp command. crc-upper dest-ip lsb Uses the upper 32 bits of the key for the hash computation. Default: crc-lower. Uses the destination IP for ECMP hashing. Default: enabled. Returns the LSB of the key as the hash. Default: crc-lower. Defaults • crc-lower • dest-ip enabled Command Modes Command History CONFIGURATION Version 8.3.11.1 Version 8.1.1.0 Version 7.6.1.0 Version 7.5.1.0 Introduced on the Z9000. Introduced on the E-Series ExaScale. Introduced on the S-Series. 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 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, but if the default algorithm does not provide satisfactory distribution of traffic, use this command to designate another algorithm. 612