Cisco Catalyst 3560-X Series, Software Configuration Manual

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 Configuring EtherChannels and Link-State Tracking
Understanding EtherChannels
Figure 1-3 Cross-Stack EtherChannel
Port-Channel Interfaces
When you create an EtherChannel, a port-channel logical interface is involved:
•
With Layer 2 ports, use the channel-group interface configuration command to dynamically create
the port-channel logical interface.
You also can use the interface port-channel port-channel-number global configuration command
to manually create the port-channel logical interface, but then you must use the channel-group
channel-group-number command to bind the logical interface to a physical port. The
channel-group-number can be the same as the port - channel-number, or you can use a new number.
If you use a new number, the channel-group command dynamically creates a new port channel.
•
With Layer 3 ports, you should manually create the logical interface by using the interface
port-channel global configuration command followed by the no switchport interface configuration
command. Then you manually assign an interface to the EtherChannel by using the channel-group
interface configuration command.
For both Layer 2 and Layer 3 ports, the channel-group command binds the physical port and the logical
interface together as shown in Figure 1-4 .
Each EtherChannel has a port-channel logical interface numbered from 1 to 48. This port-channel
interface number corresponds to the one specified with the
channel-group interface configuration
command.
Switch 1
Switch stack
Switch 2
Channel
group 1
StackWise Plus
port
connections
Switch 3
Switch A
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