Concept 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.
Load-Balancing Method
By default, LAG hashing uses the source IP, destination IP, source transmission control protocol (TCP)/user datagram protocol
(UDP) port, and destination TCP/UDP port for hash computation. For packets without a Layer 3 header, Dell EMC Networking
OS automatically uses load-balance mac source-dest-mac.
Do not configure IP hashing or MAC hashing at the same time. If you configure an IP and MAC hashing scheme at the same
time, the MAC hashing scheme takes precedence over the IP hashing scheme.
To change the IP traffic load-balancing default, use the following command.
● Replace the default IP 4-tuple method of balancing traffic over a port channel.
CONFIGURATION mode
[no] load-balance {ip-selection [dest-ip | source-ip]} | {mac [dest-mac | source-dest-mac
| source-mac]} | {tcp-udp enable} {ipv6-selection} {tunnel}| {ingress-port}
You can select one, two, or all three of the following basic hash methods:
○ ip-selection [dest-ip | source-ip] — Distribute IP traffic based on the IP destination or source address.
○ mac [dest-mac | source-dest-mac | source-mac] — Distribute IPV4 traffic based on the destination or
source MAC address, or both, along with the VLAN, Ethertype, source module ID and source port ID.
336
Interfaces