Etherchannel Overview - Cisco 3750G - Catalyst Integrated Wireless LAN Controller Configuration Manual

Understanding EtherChannels

EtherChannel Overview

An EtherChannel consists of individual Fast Ethernet or Gigabit Ethernet links bundled into a single
logical link as shown in
Figure 34-1
The EtherChannel provides full-duplex bandwidth up to 800 Mbps (Fast EtherChannel) or 8 Gbps
(Gigabit EtherChannel) 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 either Layer 2 or Layer 3 ports. The number of EtherChannels is
limited to 48. For more information, see the
page
configured to be in Layer 3 mode by using the no switchport interface configuration command. 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:
•
•
Catalyst 3750 Switch Software Configuration Guide
34-2
Figure
Typical EtherChannel Configuration
Catalyst 8500
series switch
Gigabit EtherChannel
1000BASE-X
10/100
Switched
links
Workstations
34-12. The EtherChannel Layer 3 ports are made up of routed ports. Routed ports are physical ports
Chapter 11, "Configuring Interface Characteristics."
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. Beginning with Cisco IOS Release 12.2(35)SE, instead of a
suspended state, the local port is put into an independent state and continues to carry data traffic as
would any other single link. The port configuration does not change, but the port does not participate
in the EtherChannel.
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 34
34-1.
1000BASE-X
10/100
Switched
links
Workstations
"EtherChannel Configuration Guidelines" section on
Configuring EtherChannels and Link-State Tracking
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