Users Guide
hash-algorithm seed
Select the seed value for the ECMP, LAG, and NH hashing algorithm.
S4820T
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 0
to 11.
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, 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
9.7(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 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.
FTOS 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.
NOTE: While the seed is stored separately on each port-pipe, the same seed is used across all
CAMs.
You cannot separate LAG and ECMP but you can use dierent algorithms across the chassis with the
same seed. If LAG member ports span multiple port-pipes and line cards, set the seed to the same
value on each port-pipe to achieve deterministic behavior.
If the hash algorithm conguration is removed, the hash seed does not go to the original factory default
setting.
Equal Cost Multi-Path (ECMP)
575