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Catalyst 3750 Metro Switch Command Reference
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Chapter 2 Catalyst 3750 Metro Switch Cisco IOS Commands
channel-group
Defaults
No channel groups are assigned.
No mode is configured.
Command Modes
Interface configuration
Command History
Usage Guidelines
For Layer 2 EtherChannels, you do not have to create a port-channel first by using the
interface
port-channel
global configuration command before assigning a physical port to a channel group.
Instead, you can use the
channel-group
interface configuration command. It automatically creates the
port-channel when the channel group gets its first physical port if the logical interface is not already
created. If you create the port-channel first, the
channel-group-number
can be the same as the
port
-
channel-number,
or you can use a new number. If you use a new number, the
channel-group
command dynamically creates a new port channel.
You do not have to disable the IP address that is assigned to a physical port that is part of a channel group,
but we strongly recommend that you do so.
You create Layer 3 port channels by using the
interface port-channel
command followed by the
no
switchport
interface configuration command. You should manually configure the port-channel logical
interface before putting the interface into the channel group.
After you configure an EtherChannel, configuration changes that you make on the port-channel apply to
all the physical ports assigned to the port-channel. Configuration changes applied to the physical port
affect only the port where you apply the configuration. To change the parameters of all ports in an
EtherChannel, apply configuration commands to the port-channel, for example, spanning-tree
commands or commands to configure a Layer 2 EtherChannel as a trunk.
If you do not specify
non-silent
with the
auto
or
desirable
mode, silent is assumed. The silent mode is
used when the switch is connected to a device that is not PAgP-capable and seldom, if ever, sends
packets. A example of a silent partner is a file server or a packet analyzer that is not generating traffic.
In this case, running PAgP on a physical port prevents that port from ever becoming operational.
However, it allows PAgP to operate, to attach the port to a channel group, and to use the port for
transmission. Both ends of the link cannot be set to silent.
With the
on
mode, a usable EtherChannel exists only when a port group in the
on
mode is connected to
another port group in the
on
mode.
Caution
You should use care when using the
on
mode. This is a manual configuration, and ports on both ends of
the EtherChannel must have the same configuration. If the group is misconfigured, packet loss or
spanning-tree loops can occur.
Note
Enhanced-services (ES) port cannot be bundled with non ES ports.
Release
Modification
12.1(14)AX
This command was introduced.