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To change to another algorithm, use the second command.
● Change the default (0) to another algorithm and apply it to ECMP, LAG hashing, or a particular line card.
CONFIGURATION mode
hash-algorithm {ecmp {crc16 | crc16cc | crc32MSB | crc32LSB | crc-upper | dest-ip |
flow-based-hashing {crc16|crc16cc|crc32MSB|crc32LSB|xor1|xor2|xor4|xor8|xor16}|lsb | xor1
| xor2 | xor4 | xor8 | xor16}[[hg {crc16 | crc16cc | crc32MSB | crc32LSB | xor1 | xor2 |
xor4 | xor8 | xor16}]| [lag {crc16 | crc16cc | crc32MSB | crc32LSB | xor1 | xor2 | xor4
| xor8 | xor16 }][stack-unit|linecard number | port-set number | [hg—seed seed-value |
seedseed-value
For more information about algorithm choices, refer to the command details in the IP Routing chapter of the Dell 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
Dell(conf)#hash-algorithm ecmp xor1 lag crc16
Dell(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.
● flow-based-hashing — uses flow-based-hashing followed by the algorithm crc16 |crc16cc |crc32MSB |crc32LSB |xor1
|xor2 |xor4 |xor8 | xor16.
● lsb —always 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.
Server Ports
By default, the switch allows the server ports to come up as switch ports in no shut mode, ready to switch traffic.
Default Configuration without Start-up Config
This feature is enabled by default and can be enabled on reload by deleting the start-up config file.
On reload, all the server ports (1-32) come up as switch ports in No Shut mode. Uplinks remain in Shut mode ensuring that there
are no network loops.
With this feature, you can install servers and test their connectivity by running applications on the servers, even before
configuring VLAN membership, STP on all interfaces or uplinks.
Interfaces
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