Filter
Top Products
37-17
Catalyst 2960 and 2960-S Switch Software Configuration Guide
OL-8603-09
Chapter 37 Configuring EtherChannels and Link-State Tracking
Configuring EtherChannels
You also can configure a single port within the group for all transmissions and use other ports for hot
standby. The unused ports in the group can be swapped into operation in just a few seconds if the selected
single port loses hardware-signal detection. You can configure which port is always selected for packet
transmission by changing its priority with the pagp port-priority interface configuration command. The
higher the priority, the more likely that the port will be selected.
Note The switch supports address learning only on aggregate ports even though the physical-port keyword is
provided in the CLI. The pagp learn-method command and the pagp port-priority command have no
effect on the switch hardware, but they are required for PAgP interoperability with devices that only
support address learning by physical ports.
When the link partner of the switch is a physical learner (such as a Catalyst 1900 series switch), we
recommend that you configure the Catalyst 2960 or 2960-S switch as a physical-port learner by using
the pagp learn-method physical-port interface configuration command. Set the load-distribution
method based on the source MAC address by using the port-channel load-balance src-mac global
configuration command. The switch then sends packets to the Catalyst 1900 switch using the same port
in the EtherChannel from which it learned the source address. Only use the pagp learn-method
command in this situation.
Beginning in privileged EXEC mode, follow these steps to configure your switch as a PAgP
physical-port learner and to adjust the priority so that the same port in the bundle is selected for sending
packets. This procedure is optional.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
interface interface-id Specify the port for transmission, and enter interface
configuration mode.
Step 3
pagp learn-method physical-port Select the PAgP learning method.
By default, aggregation-port learning is selected, which means
the switch sends packets to the source by using any of the ports
in the EtherChannel. With aggregate-port learning, it is not
important on which physical port the packet arrives.
Select physical-port to connect with another switch that is a
physical learner. Make sure to configure the port-channel
load-balance global configuration command to src-mac as
described in the “Configuring EtherChannel Load Balancing”
section on page 37-15.
The learning method must be configured the same at both ends
of the link.
Step 4
pagp port-priority priority Assign a priority so that the selected port is chosen for packet
transmission.
For priority, the range is 0 to 255. The default is 128. The higher
the priority, the more likely that the port will be used for PAgP
transmission.
Step 5
end Return to privileged EXEC mode.