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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 21 Configuring EtherChannel
Understanding EtherChannel
In
Figure 21-3
, an EtherChannel of four workstations communicates with a router. Because the router is
a single-MAC-address device, source-based forwarding on the switch EtherChannel ensures that the
switch uses all available bandwidth to the router. The router is configured for destination-based
forwarding because the large number of workstations ensures that the traffic is evenly distributed from
the router EtherChannel.
Use the option that provides the greatest variety in your configuration. For example, if the traffic on a
channel is going only to a single MAC address, using the destination-MAC address always chooses the
same link in the channel; using source addresses or IP addresses might result in better load balancing.
Figure 21-3 Load Distribution and Forwarding Methods
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Cisco router
with destination-based
forwarding enabled
EtherChannel
Catalyst 3550 switch
with source-based
forwarding enabled