Dell Force10 S4820T FTOS Command Reference Guide - Page 519

Related Commands 12 - 23 24 - 35 36 - 47 Compression Enabled shift [0 - 11] Compression Disabled rotate [0 - 11] Compression Disabled shift [0 - 11] load-balance (E-Series) Change the traffic balancing method. hash-algorithm ecmp c s Change the hash algorithm used to distribute traffic flows 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 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 Command Modes crc-lower, dest-ip enabled CONFIGURATION Command History Version 7.6.1.0 Version 7.5.1.0 Introduced on S-Series Introduced on 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 the user hasn't 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, then 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 traffic across the members. Equal Cost Multi-Path | 519