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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 21 Configuring EtherChannel
Configuring EtherChannel
Configuring the Physical Interfaces
Beginning in privileged EXEC mode, follow these steps to assign an Ethernet interface to a Layer 3
EtherChannel:
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface interface-id
Enter interface configuration mode, and specify a physical
interface to configure.
Valid interfaces include physical interfaces.
Up to eight interfaces of the same type and speed can be
configured for the same group.
Step 3
no ip address
Ensure that there is no IP address assigned to the physical
interface.
Step 4
channel-group channel-group-number mode
{auto [non-silent] | desirable [non-silent] | on}
Assign the interface to a channel group, and specify the PAgP
mode (the default mode is auto silent).
For channel-group-number, the range is 1 to 64. This number
must be the same as the port-channel-number (logical port)
configured in the
“Creating Port-Channel Logical Interfaces”
section on page 21-11
.
Each EtherChannel can consist of up to eight compatibly
configured Ethernet interfaces.
For mode, select one of these keywords:
•
auto—Enables PAgP only if a PAgP device is detected. It
places an interface into a passive negotiating state, in which
the interface responds to PAgP packets it receives but does
not start PAgP packet negotiation.
•
desirable—Unconditionally enables PAgP. It places an
interface into an active negotiating state, in which the
interface starts negotiations with other interfaces by sending
PAgP packets.
•
on—Forces the interface to channel without PAgP. With the
on mode, a usable EtherChannel exists only when an
interface group in the on mode is connected to another
interface group in the on mode.
•
non-silent—If your switch is connected to a partner that is
PAgP capable, you can configure the switch interface for
nonsilent operation. You can configure an interface with the
non-silent keyword for use with the auto or desirable mode.
If you do not specify non-silent with the auto or desirable
mode, silent is assumed. The silent setting is for connections
to file servers or packet analyzers; this setting allows PAgP
to operate, to attach the interface to a channel group, and to
use the interface for transmission.
For information on compatible PAgP modes for the switch and its
partner, see the
“PAgP Modes” section on page 21-4
.