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Selection of Algorithms is available under flow-based-hashing enabling another level of randomness in hash selection. CLI to
enable flow-based hashing is shown in the given example:
Dell_GW1(conf)#hash-algorithm ecmp flow-based-hashing ?
crc16 CRC16_BISYNC - 16 bit CRC16-bisync polynomial(default)
crc16cc CRC16_CCITT - 16 bit CRC16 using CRC16-CCITT polynomial
crc32MSB CRC32_UPPER - MSB 16 bits of computed CRC32
crc32LSB CRC32_LOWER - LSB 16 bits of computed CRC32
xor1 CRC16_BISYNC_AND_XOR1 - Upper 8 bits of CRC16-BISYNC and lower 8
bits of xor1
xor2 CRC16_BISYNC_AND_XOR2 - Upper 8 bits of CRC16-BISYNC and lower 8
bits of xor2
xor4 CRC16_BISYNC_AND_XOR4 - Upper 8 bits of CRC16-BISYNC and lower 8
bits of xor4
xor8 CRC16_BISYNC_AND_XOR8 - Upper 8 bits of CRC16-BISYNC and lower 8
bits of xor8
xor16 CR16 - 16 bit XOR]
Example to view show hash-algorithm:
DellEMC(conf)#hash-algorithm ecmp flow-based-hashing crc16
DellEMC(conf)#end
DellEMC#show hash-algorithm
Hash-Algorithm
linecard 0 Port-Set 0
Seed 185270328
Hg-Seed 185282673
EcmpFlowBasedHashingAlgo- crc16
EcmpAlgo- crc32MSB LagAlgo- crc32LSB HgAlgo- crc16
Figure 40. After Polarization Effect
Traffic flow after enabling flow-based hashing
318
Equal Cost Multi-Path (ECMP)