Administrator Guide

Assigning an IP Address to a Port Channel
You can assign an IP address to a port channel and use port channels in Layer 3 routing protocols.
To assign an IP address, use the following command.
• Configure an IP address and mask on the interface.
INTERFACE mode
ip address ip-address mask [secondary]
• ip-address mask: enter an address in dotted-decimal format (A.B.C.D). The mask must be in slash format (/24).
• secondary: the IP address is the interface’s backup IP address. You can configure 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 traffic evenly over channel members in a port channel (LAG).
The hash algorithm distributes traffic among Equal Cost Multi-path (ECMP) paths and LAG members. The distribution is based on a flow,
except for packet-based hashing. A flow is identified by the hash and is assigned to one link. In packet-based hashing, a single flow can be
distributed on the LAG and uses one link.
Packet based hashing is used to load balance traffic across a port-channel based on the IP Identifier field within the packet. Load
balancing uses source and destination packet information to get the greatest advantage of resources by distributing traffic over multiple
paths when transferring data to a destination.
Dell Networking OS allows you to modify the hashing algorithms used for flows and for fragments. The load-balance and hash-algorithm
commands are available for modifying the distribution algorithms.
NOTE:
Hash-based load-balancing on multi-protocol label switching (MPLS) does not work when you enable packet-
based hashing (load-balance ip-selection packet-based).
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 | lsb |
xor1 | xor2 | xor4 | xor8 | xor16} | hg {crc16 | crc16cc | crc32MSB | crc32LSB | xor1 |
xor2 | xor4 | xor8 | xor16} | hg-seed seed-value | lag {crc16 | crc16cc | crc32MSB |
crc32LSB | xor1 | xor2 | xor4 | xor8 | xor16} | seed seed-value } [linecard slot-id [port-
set port-pipe]]
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.
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Interfaces