Users Guide

ECMP commands
enhanced-hashing
Ensures that existing traffic flows are not remapped when a member link goes down.
Syntax
enhanced-hashing resilient-hashing {lag | ecmp}
Parameters
● resilient-hashing—Enter the keyword to enable enhanced-hashing.
● {ecmp | lag}—Enter the keyword to enable resilient hashing for a port channel or ECMP group.
Defaults Disabled
Command Mode CONFIGURATION
Usage
Information
The no version of this command disables resilient hashing. For supported platforms, see Supported
platforms.
Example
OS10(config)# enhanced-hashing resilient-hashing ecmp
OS10(config)# enhanced-hashing resilient-hashing lag
Supported
Releases
10.4.3.0 or later
hash-algorithm
Changes the hash algorithm that distributes traffic flows across ECMP paths and the link aggregation group (LAG).
Syntax
hash-algorithm {ecmp | lag | seed {seed-value}} {crc | crc16cc | crc32LSB |
crc32MSB | xor | xor1 | xor2 | xor4 | xor8 | random}
Parameters
● ecmp—Enables the ECMP hash configuration.
● lag—Enables the LAG hash configuration for Layer 2 (L2) only.
● seed—Changes the hash algorithm seed value to get a better hash value.
● seed-value—Enter a hash algorithm seed value, from 0 to 4294967295.
● crc—Enables the cyclic redundancy check (CRC) polynomial for hash computation.
● crc16cc—16 bit CRC16 using CRC16-CCITT polynomial
● crc32LSB—LSB 16 bits of computed CRC32(default)
● crc32MSB—MSB 16 bits of computed CRC32
● xor — Enables upper 8 bits of CRC and lower 8 bits of XOR value for computation.
● xor1—Enables upper 8 bits of CRC16-BISYNC and lower 8 bits of xor1
● xor2—Enables upper 8 bits of CRC16-BISYNC and lower 8 bits of xor2
● xor4—Enables upper 8 bits of CRC16-BISYNC and lower 8 bits of xor4
● xor8—Enables upper 8 bits of CRC16-BISYNC and lower 8 bits of xor8
● random — Enables a hash algorithm random seed value for ECMP or LAG hash computation.
Default
crc
Command Mode CONFIGURATION
Usage
Information
The hash value calculated with this command is unique to the entire system. Different hash algorithms
are based on the number of port-channel members and packet values. The default hash algorithm yields
the most balanced results in various test scenarios, but if the default algorithm does not provide a
satisfactory distribution of traffic, use this command to designate another algorithm.
When a port-channel member leaves or is added to the port-channel, the hash algorithm recalculates to
balance traffic across the members. The no version of this command returns the value to the default.
892 Layer 3