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 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.
Their syntax and implementation are somewhat different between the E-Series and the C-Series and S-
Series
NOTE: Hash-based load-balancing on MPLS does not work when packet-based hashing (load-
balance ip-selection packet-based) is enabled.
Load-Balancing Method
For LAG hashing on the source IP, destination IP, source transmission control protocol (TCP)/user
datagram protocol (UDP) port, and destination TCP/UDP port are used for hash computation by default.
For packets without a Layer 3 header, Dell 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.
– tcp-udp enable — Distribute traffic based on the TCP/UDP source and destination ports.
– ingress-port — Option to Source Port Id for ECMP/ LAG hashing.
Interfaces
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