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Catalyst 2940 Switch Software Configuration Guide
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Chapter25 Configuring EtherChannels
Configuring EtherChannels
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 directs transmissi ons ba sed 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 Catalyst 2950 switch for
source-MAC load distribution.
The Catalyst 2940 switch supports address learning only on a gg regate po rts even thoug h t he
physical-port keyword is provided in the command-line interface (CLI). The pagp learn-method and
the pagp port-priority interface configuration command have no effect on the switch hardware.
Note You should not set the learn method to physical-port because the switch is an aggregate-learning device.
If the link partner to the switch is a physical learner that has the channel-group interface configuration
command set to auto or desirable, the switch automatically uses the load-distribution method based on
the source MAC address, regardless of the configured load distribution method.
If the link partner to the Catalyst 2940 switch is a physical learner that has the channel-group interface
configuration command set to on, set the load-distribution method based on the source MAC address by
using the port-channel load-balance src-mac global configuration command.
Configuring the LACP Port Priority
You can set the priority for each port in an EtherChannel that is configured for LACP by using the
lacp port-priority privileged EXEC command. The range is from 1 to 65535. Beginni ng in privileged
EXEC mode, follow these steps to configure the LACP port priority:
Step4 show etherchannel load-balance Verify your entries.
Step5 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Enter interface configuration mode, and specify the interface for
transmission.
Step3 lacp port-priority priority-value Select the LACP port priority value.
For priority-value, the range is 1 to 65535. By default, the priority value
is 32768. The lower the range, the more likely that the interface will be
used for LACP transmission.
Step4 end Return to privileged EXEC mode.