You configure the load-balancing and forwarding method by using the port-channel load-balance global
configuration command.
Related Topics
Configuring EtherChannel Load-Balancing
EtherChannel Configuration Guidelines, on page 120
Layer 2 EtherChannel Configuration Guidelines, on page 122
Default EtherChannel Configuration, on page 119
Layer 3 EtherChannel Configuration Guidelines, on page 123
MAC Address Forwarding
With source-MAC address forwarding, when packets are forwarded to an EtherChannel, they are distributed
across the ports in the channel based on the source-MAC address of the incoming packet. Therefore, to provide
load-balancing, packets from different hosts use different ports in the channel, but packets from the same host
use the same port in the channel.
With destination-MAC address forwarding, when packets are forwarded to an EtherChannel, they are distributed
across the ports in the channel based on the destination host’s MAC address of the incoming packet. Therefore,
packets to the same destination are forwarded over the same port, and packets to a different destination are
sent on a different port in the channel.
With source-and-destination MAC address forwarding, when packets are forwarded to an EtherChannel, they
are distributed across the ports in the channel based on both the source and destination MAC addresses. This
forwarding method, a combination source-MAC and destination-MAC address forwarding methods of load
distribution, can be used if it is not clear whether source-MAC or destination-MAC address forwarding is
better suited on a particular switch. With source-and-destination MAC-address forwarding, packets sent from
host A to host B, host A to host C, and host C to host B could all use different ports in the channel.
Related Topics
Configuring EtherChannel Load-Balancing
EtherChannel Configuration Guidelines, on page 120
Layer 2 EtherChannel Configuration Guidelines, on page 122
Default EtherChannel Configuration, on page 119
Layer 3 EtherChannel Configuration Guidelines, on page 123
IP Address Forwarding
With source-IP address-based forwarding, when packets are forwarded to an EtherChannel, they are distributed
across the ports in the EtherChannel based on the source-IP address of the incoming packet. Therefore, to
provide load-balancing, packets from different IP addresses use different ports in the channel, but packets
from the same IP address use the same port in the channel.
With destination-IP address-based forwarding, when packets are forwarded to an EtherChannel, they are
distributed across the ports in the EtherChannel based on the destination-IP address of the incoming packet.
Therefore, to provide load-balancing, packets from the same IP source address sent to different IP destination
addresses could be sent on different ports in the channel. But packets sent from different source IP addresses
to the same destination IP address are always sent on the same port in the channel.
Catalyst 2960-XR Switch Layer 2 Configuration Guide, Cisco IOS Release 15.0(2)EX1
116 OL-29424-01
Configuring EtherChannels
Load-Balancing and Forwarding Methods
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