Users Guide

– secondary: the IP address is the interface’s backup IP address. You can congure up to eight secondary IP addresses.
Deleting or Disabling a Port Channel
To delete or disable a port channel, use the following commands.
• Delete a port channel.
CONFIGURATION mode
no interface portchannel channel-number
• 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 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 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.
The nh-ecmp option allows you to change the hash value for recursive ECMP routes independently of non-recursive ECMP routes.
This option provides for better trac distribution over available equal cost links that involve a recursive next hop lookup.
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 to another algorithm.
CONFIGURATION mode
Example of the hash-algorithm Command
Dell(conf)#hash-algorithm ecmp xor 26 lag crc 26 nh-ecmp checksum 26
Dell(conf)#
Interfaces
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