Understanding Port-Channel Interfaces - Cisco Catalyst 2950 Software Configuration Manual

Chapter 30 Configuring EtherChannels
Understanding EtherChannels
Figure 30-1 Typical EtherChannel Configuration
Catalyst 8500
series switch
Gigabit EtherChannel
1000BASE-X 1000BASE-X
10/100 10/100
Switched Switched
links links
Workstations Workstations
Each EtherChannel can consist of up to eight compatibly configured Ethernet interfaces. All interfaces
in each EtherChannel must be the same speed, and all must be configured as Layer 2 interfaces.
The network device to which your switch is connected can impose its own limits on the number of
Note
interfaces in the EtherChannel. For Catalyst 2950 and Catalyst 2955 switches, the number of
EtherChannels is limited to six with eight ports per EtherChannel.
If a link within an EtherChannel fails, traffic previously carried over that failed link changes to the
remaining links within the EtherChannel. A trap is sent for a failure, identifying the switch, the
EtherChannel, and the failed link. Inbound broadcast and multicast packets on one link in an
EtherChannel are blocked from returning on any other link of the EtherChannel.

Understanding Port-Channel Interfaces

When you create an EtherChannel for Layer 2 interfaces, a logical interface is dynamically created, as
shown in Figure 30-2. You then manually assign an interface to the EtherChannel by using the
channel-group interface configuration command.
Each EtherChannel has a logical port-channel interface numbered from 1 to 6.
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
30-2
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