Dell Force10 Z9000 FTOS Command Line Reference Guide for the Z9000 System FTOS - Page 611

Related Commands The different hash algorithms are based on the number of Port Channel members and packet values. The default hash algorithm (number 0) yields the most balanced results in various test scenarios, but if the default algorithm does not provide a satisfactory distribution of traffic, use the hash-algorithm command to designate another algorithm. When a Port Channel member leaves or is added to the Port Channel, the hash algorithm is recalculated to balance traffic across the members. On TeraScale, if the keyword ECMP or LAG is not entered, FTOS assumes it to be common for both. If the keyword ECMP orLAG is entered separately, both fall in the range of 0 to 23 or 24 to 47 because compression enable/disable is common for both keywords. TeraScale and ExaScale support the range 0 to 47. The default for ExaScale is 24. load-balance (E-Series) - Change the traffic balancing method. hash-algorithm d Select the d value for the ECMP, LAG, and NH hashing algorithm. E-Series Syntax Parameters hash-algorithm d value [linecard slot] [port-set number] d value linecard slot port-set number Enter the keyword d followed by the d value. The range is 0 to 4095. Enter the keyword linecard followed by the linecard slot number. Enter the keywords port-set followed by the linecard port-pipe number. Defaults Command Modes Command History none CONFIGURATION Version 8.3.10.0 Introduced on the E-Series. Usage Information Deterministic ECMP sorts ECMPs in order even though RTM provides them in a random order. However, the hash algorithm uses as a d the lower 12 bits of the chassis MAC, which yields a different hash result for every chassis. This means that for a given flow, even though the prefixes are sorted, two unrelated chassis selects different hops. FTOS provides a CLI-based solution for modifying the hash d to ensure that on each configured system, the ECMP selection is same. When configured, the same d is set for ECMP, LAG, and NH, and is used for incoming traffic only. NOTE: While the d is stored separately on each port-pipe, the same d is used across all CAMs. 611