Service Manual

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.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
8.3.11.1 Introduced on the Z9000.
8.3.10.0 Introduced on the S4810.
8.1.1.0 Introduced on the E-Series ExaScale.
7.8.1.0 Added the nh-ecmp option.
7.7.1.1 Added the nh-ecmp option.
Usage Information To ensure that CRC is not used for LAG, set the default hash-algorithm method on ExaScale systems. For
example,hash-algorithm ecmp xor lag checksum nh-ecmp checksum.
The hash value calculated with the hash-algorithm command is unique to the entire chassis. The hash
algorithm command with the stack—unit option changes the hash for a particular stack—unit by applying
the mask specied in the IPSA and IPDA elds.
The stack-unit option is applicable with the lag-hash-align microcode only. Any other microcode returns an
error message as follows:
• Dell(conf)#hash-algorithm linecard 5 ip-sa-mask ff ip-da-mask ff
• % Error: This command is not supported in the current microcode
configuration
In addition, the linecard number ip-sa-mask value ip-da-mask value option has the
following behavior to maintain bi-directionality:
• When hashing is done on both IPSA and IPDA, the ip-sa-mask and ip-da-mask values must be
equal. (Single Linecard).
• When hashing is done only on IPSA or IPDA, Dell Networking OS maintains bi-directionality with masks
set to XX 00 for stack-unit 1 and 00 XX for stack-unit 2 (ip-sa-mask and ip-da-mask). The mask
value must be the same for both stack-units when using multiple stack-units as ingress (where XX is any
value from 00 to FF for both stack-units). For example, assume that trac is owing between linecard 1
and linecard 2:
• hash-algorithm linecard 1 ip-sa-mask aa ip-da-mask 00
• hash-algorithm linecard 2 ip-sa-mask 00 ip-da-mask aa
The dierent 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 trac, use the hash-algorithm command to
designate another algorithm.
Equal Cost Multi-Path (ECMP)
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