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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter21 Configuring EtherChannel
Configuring EtherChannel
Beginning in privileged EXEC mode, follow these steps to confi gure Et her Cha nnel l oad ba lan cing :
To return EtherChannel load balancing to the default configuration, use the no port-channel
load-balance global configuration command.
Configuring the PAgP Learn Method and Priority
Network devices are classified as PAgP physical learners or aggregate-port learners. A device is a
physical learner if it learns addresses by physical ports and dir ects t ran smi ssions base d o n that
knowledge. A device is an aggregate-port learner if it learns addresses by aggregate ports.
For compatibility with Catalyst 1900 series switches, configure the PAgP learning method on the
Catalyst 3550 switches to learn source-MAC addresses on the physical port. The swi tch t hen sends
packets to the Catalyst 1900 switch using the same interface in the EtherCha nnel from which it learned
the source address.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 port-channel load-balance {dst-mac | src-mac} Configure an EtherChannel load-balancing method.
The default is src-mac.
Select one of these keywords to determine the load-distribution
method:
dst-macLoad distribution is based on the destination-host
MAC address of the incoming packet. Packets to the same
destination are sent on the same port, but packets to different
destinations are sent on different ports in the channel.
src-macLoad distribution is based on the source-MAC
address of the incoming packet. Packets from different hosts
use different ports in the channel, but packets from the same
host use the same port in the channel.
When src-mac is used, load distribution based on the source
and destination IP address is also enabled. For all IP traffic
being routed, the switch chooses a port for transmission
based on the source and destination IP address. Packets
between two IP hosts always use the same port for packet
transmission, but packets between any other pair of hosts
might use a different transmission port.
Step3 end Return to privileged EXEC mode.
Step4 show etherchannel load-balance Verify your entries.
Step5 copy running-config startup-config (Optional) Save your entries in the configuration file.