Port-Channel Interfaces - Cisco Catalyst 2975 Software Configuration Manual

Understanding EtherChannels
Figure 37-3
Stack port
connections

Port-Channel Interfaces

When you create a Layer 2 EtherChannel, a port-channel logical interface is involved. You can create
the EtherChannel in these ways:
•
•
Each EtherChannel has a port-channel logical interface numbered from 1 to 6. This port-channel
interface number corresponds to the one specified with the channel-group interface configuration
command.
Catalyst 2975 Switch Software Configuration Guide
37-4
Cross-Stack EtherChannel
Catalyst 2975 switch stack
Switch 1
Switch 2
Switch 3
Use the channel-group interface configuration command. This command automatically creates the
port-channel logical interface when the channel group gets its first physical port. The
channel-group command binds the physical (10/100/1000 ports) and the logical ports together as
shown in Figure 37-4.
Use the interface port-channel port-channel-number global configuration command to manually
create the port-channel logical interface. Then use the channel-group channel-group-number
interface configuration 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.
Chapter 37 Configuring EtherChannels and Link-State Tracking
Switch A
Channel
group 1
OL-19720-02