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Catalyst2950 and Catalyst2955 Switch Software Configuration Guide
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Chapter31 Configuring EtherChannels
Understanding EtherChannels
Figure31-1 Typical EtherChannel Configuration
Each EtherChannel can consist of up to eight compatibly configur ed Ethe rn et i nte rface s. A ll in te rface s
in each EtherChannel must be the same speed, and all mu st b e c onfigured a s L aye r 2 interfaces.
Note The network device to which your switch is connected can im pose i ts own limit s on t he nu mbe r of
interfaces in the EtherChannel. For Catalyst 2950 and Catalyst 2955 switches, the number of
EtherChannels is limited to six with eight ports per Ether Chann el .
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 E the rChann el.
Understanding Port-Channel Interfaces
When you create an EtherChannel for Layer 2 interfaces, a logical interface is dynamically created, as
shown in Figure 31-2. 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.
101237
Catalyst 8500
series switch
Gigabit EtherChannel
Workstations
10/100
Switched
links
Workstations
10/100
Switched
links
1000BASE-X 1000BASE-X