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 EMC 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 EMC 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.
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 traffic 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
386
Interfaces