Cisco Systems 3750E manual Port-Channel Interfaces, 37-4

Chapter 37 Configuring EtherChannels and Link-State Tracking

Understanding EtherChannels

Figure 37-3 Cross-Stack EtherChannel

Catalyst 3750-E switch stack

Switch 1

StackWise Plus port connections

Switch 2 Switch A

Channel group 1

Switch 3

159894

Port-Channel Interfaces

When you create an EtherChannel, a port-channel logical interface is involved:

•With Layer 2 ports, use the channel-groupinterface configuration command to dynamically create the port-channel logical interface.

You also can use the interface port-channelport-channel-numberglobal configuration command to manually create the port-channel logical interface, but then you must use the channel-groupchannel-group-numbercommand to bind the logical interface to a physical port. The channel-group-numbercan be the same as the port-channel-number,or you can use a new number. If you use a new number, the channel-groupcommand dynamically creates a new port channel.

•With Layer 3 ports, you should manually create the logical interface by using the interface port-channelglobal configuration command followed by the no switchport interface configuration command. Then you manually assign an interface to the EtherChannel by using the channel-groupinterface configuration command.

For both Layer 2 and Layer 3 ports, the channel-groupcommand binds the physical port and the logical interface together as shown in Figure 37-4.

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-groupinterface configuration command.

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

37-4 OL-9775-02