Etherchannel Overview - Cisco 3020 - Catalyst Blade Switch Configuration Manual

Understanding EtherChannels

EtherChannel Overview

An EtherChannel consists of individual Gigabit Ethernet links bundled into a single logical link as shown
in Figure
Figure 28-1
Gigabit EtherChannel
In Figure
between your switch and another switch or host.
Each EtherChannel can consist of up to eight compatibly configured Ethernet ports. All ports in each
EtherChannel must be configured as Layer 2 ports. The number of EtherChannels is limited to 48. For
more information, see the
You can configure an EtherChannel in one of these modes: Port Aggregation Protocol (PAgP), Link
Aggregation Control Protocol (LACP), or On. Configure both ends of the EtherChannel in the same
mode:
•
•
If a link within an EtherChannel fails, traffic previously carried over that failed link moves to the
remaining links within the EtherChannel. If traps are enabled on the switch, a trap is sent for a failure
that identifies 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.
Cisco Catalyst Blade Switch 3020 for HP Software Configuration Guide
28-2
28-1.
Typical EtherChannel Configuration
Catalyst 6500
series switch
Blade
Switch
Blade Blade
Server 1
Server 10
28-1, the EtherChannel provides full-duplex bandwidth up to 8 Gbps (Gigabit EtherChannel)
"EtherChannel Configuration Guidelines" section on page
When you configure one end of an EtherChannel in either PAgP or LACP mode, the system
negotiates with the other end of the channel to determine which ports should become active.
Incompatible ports are suspended.
When you configure an EtherChannel in the on mode, no negotiations take place. The switch forces
all compatible ports to become active in the EtherChannel. The other end of the channel (on the other
switch) must also be configured in the on mode; otherwise, packet loss can occur.
Chapter 28 Configuring EtherChannels and Layer 2 Trunk Failover
28-9.
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