Service Manual

Term heading Description heading
When a member leaves or is added to the ECMP group, the hash algorithm is recalculated to balance trac
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 number. The range is from 1 to
6.
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-specic. For command information about other platforms, refer to the relevant Dell
Networking OS Command Line Reference Guide.
The following is a list of the Dell Networking OS version history for this command.
Version Description
9.8(0.0) Introduced on the S3048-ON and S4048-ON.
9.7(0.0) Introduced on the S6000-ON.
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 dierent hash result
for every chassis. This behavior means that for a given ow, even though the prexes are sorted, two
unrelated chassis select dierent hops.
FTOS provides a CLI-based solution for modifying the hash seed to ensure that on each congured system,
the ECMP selection is same. When congured, the same seed is set for ECMP, LAG, and NH, and is used
for incoming trac only.
Equal Cost Multi-Path (ECMP)
531