Concept Guide

• Disable a port channel.
shutdown
When you disable a port channel, all interfaces within the port channel are operationally down also.
Load Balancing Through Port Channels
Dell EMC Networking OS uses hash algorithms for distributing trac evenly over channel members in a port channel (LAG).
The hash algorithm distributes trac among Equal Cost Multi-path (ECMP) paths and LAG members. The distribution is based on a ow,
except for packet-based hashing. A ow is identied by the hash and is assigned to one link. In packet-based hashing, a single ow can be
distributed on the LAG and uses one link.
Packet based hashing is used to load balance trac across a port-channel based on the IP Identier eld within the packet. Load balancing
uses source and destination packet information to get the greatest advantage of resources by distributing trac over multiple paths when
transferring data to a destination.
Dell EMC Networking OS allows you to modify the hashing algorithms used for ows and for fragments. The load-balance and hash-
algorithm commands are available for modifying the distribution algorithms.
Changing the Hash Algorithm
The load-balance command selects the hash criteria applied to port channels.
If you do not obtain even distribution with the load-balance command, you can use the hash-algorithm command to select the
hash scheme for LAG, ECMP and NH-ECMP. You can rotate or shift the 12–bit Lag Hash until the desired hash is achieved.
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 EMC Networking OS
Command Reference Guide.
• Change to another algorithm.
CONFIGURATION mode
hash-algorithm [ecmp{crc16|crc16cc|crc32LSB|crc32MSB|crc-upper|dest-ip|lsb|xor1|xor2|xor4|
xor8|xor16}]
Example of the hash-algorithm Command
The hash-algorithm command is specic to ECMP group. The default ECMP hash conguration 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:
Interfaces
437