Service Manual
Term heading Description heading
The dierent 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 trac, 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 trac across
the members.
hash-algorithm seed
Select the seed value for the ECMP, LAG, and NH hashing algorithm.
Syntax
hash-algorithm seed value [stack-unitslot/port] [port-set number]
Parameters
seed value Enter the keyword seed then the seed value. The range is from 0 to 2,147,483,646.
stack–unit slot/port Enter the keyword stack-unit then the slot/port[subport] number.
port-set number Enter the keyword port-set then the port-pipe number. The value is 0.
Defaults None
Command Modes CONFIGURATION
Command History
This guide is platform-specic. For command information about other platforms, see the relevant Dell Networking
OS Command Line Reference Guide.
Version Description
9.8(0.0P5) Introduced on the S4048-ON.
9.8(0.0P2) Introduced on the S3048-ON.
9.7(0.0) Introduced on the S6000-ON.
9.2(1.0) Introduced on the Z9500.
8.3.19.0 Introduced on the S4820T.
8.3.11.1 Introduced on the Z9000.
8.3.7.0 Introduced on the S4810.
8.3.1.0 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 seed the lower 12 bits of the chassis MAC, which yields a dierent hash result for every
chassis. This behavior means that for a given ow, even though the prexes are sorted, two unrelated chassis
select dierent hops.
Dell provides a CLI-based solution for modifying the hash seed to ensure that on each congured system, the
ECMP selection is same. When congured, the same seed is set for ECMP, LAG, and NH, and is used for incoming
trac only.
586 Equal Cost Multi-Path (ECMP)