Users Guide

CONFIGURATION mode
hash-algorithm {algorithm-number | {ecmp {crc16 | crc16cc | crc32MSB | crc32LSB | crc-
upper | dest-ip | lsb | xor1 | xor2 | xor4 | xor8 | xor16} [number] hg {crc16 | crc16cc |
crc32MSB | crc32LSB | xor1 | xor2 | xor4 | xor8 | xor16} stack-unit stack-unit-number |
port-set port-pipe | hg-seed seed-value stack-unit | lag {checksum | crc | xor} [number]
nh-ecmp {checksum | crc | xor}[number] stack—unit number ip-sa-mask value ip-da-mask
value | seed seed-value }
For more information about algorithm choices, refer to the command details in the IP Routing chapter of the Dell EMC
Networking OS Command Reference Guide.
● Change the Hash algorithm seed value to get better hash value
Hash seed is used to compute the hash value. By default hash seed is chassis MAC 32 bits. we can also change the hash
seed by the following command.
CONFIGURATION mode
hash-algorithm seed {seed value}
● Change to another algorithm.
CONFIGURATION mode
hash-algorithm [ecmp{crc16|crc16cc|crc32LSB|crc32MSB|crc-upper|dest-ip|lsb|xor1|xor2|
xor4|xor8|xor16}]
DellEMC(conf)#hash-algorithm ecmp xor 26 lag crc 26 nh-ecmp checksum 26
DellEMC(conf)#
The hash-algorithm command is specific to ECMP group. The default ECMP hash configuration is crc-lower. This
command takes the lower 32 bits of the hash key to compute the egress port. Other options for ECMP hash-algorithms are:
● crc16 — uses 16 bit CRC16-bisync polynomial
● crc16cc — uses 16 bit CRC16 using CRC16-CCITT polynomial
● crc32LSB — uses LSB 16 bits of computed CRC32
● crc32MSB — uses MSB 16 bits of computed CRC32(default)
● crc-upper — uses the upper 32 bits of the hash key to compute the egress port.
● dest-ip — uses destination IP address as part of the hash key.
● lsb — uses the least significant bit of the hash key to compute the egress port.
● xor1 — uses Upper 8 bits of CRC16-BISYNC and lower 8 bits of xor1
● xor2 — Upper 8 bits of CRC16-BISYNC and lower 8 bits of xor2
● xor4 —Upper 8 bits of CRC16-BISYNC and lower 8 bits of xor4
● xor8 — Upper 8 bits of CRC16-BISYNC and lower 8 bits of xor8
● xor16 — uses 16 bit XOR.
Bulk Configuration
Bulk configuration allows you to determine if interfaces are present for physical interfaces or configured for logical interfaces.
Interface Range
An interface range is a set of interfaces to which other commands may be applied and may be created if there is at least one
valid interface within the range.
Bulk configuration excludes from configuration any non-existing interfaces from an interface range. A default VLAN may be
configured only if the interface range being configured consists of only VLAN ports.
The interface range command allows you to create an interface range allowing other commands to be applied to that
range of interfaces.
The interface range prompt offers the interface (with slot and port information) for valid interfaces. The maximum size of an
interface range prompt is 32. If the prompt size exceeds this maximum, it displays (...) at the end of the output.
Interfaces
379