Dell Force10 S25N-S50N FTOS Configuration Guide FTOS 8.4.2.7 E-Series TeraScal - Page 334

www.dell.com | support.dell.com Configurable ECMP Hash Algorithm (C- and S-Series) c s Configurable ECMP Hash Algorithm (C- and S-Series) is available on platforms: On C-Series and S-Series, the hash-algorithm command is specific to ECMP groups and has a different default from the E-Series (see Configurable Hash Algorithm (E-Series)). The default ECMP hash configuration is crc-lower, which takes the lower 32 bits of the hash key to compute the egress port. The hash value calculated with the hash algorithm is unique to the entire chassis. Other options for the ECMP hash-algorithm are: • crc-upper - Uses the upper 32 bits of the hash key to compute the egress port. • dest-ip - Uses destination IP address as part of the hash key. • lsb - Always uses the least significant bit of the hash key to compute the egress port. To change to a different hash scheme for ECMP, use the following command in the CONFIGURATION mode: Command Syntax hash-algorithm ecmp {crc-lower | crc-upper | dest-ip | lsb} Default: crc-lower Command Mode CONFIGURATION Purpose Change to another algorithm. The different hash algorithms for ECMP 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. 334 | Equal Cost Multi-Path