Specifications

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Catalyst 2950 and Catalyst 2955 Switch Command Reference
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Chapter 2 Cisco IOS Commands
channel-group
Defaults No channel groups are assigned.
There is no default mode.
Command Modes Interface configuration
Command History
Usage Guidelines You must specify the mode when entering this command. If the mode is not entered, an Ethernet interface
is not assigned to an EtherChannel group, and an error message appears.
You do not have to create a port-channel interface before assigning a physical interface to a channel
group. A port-channel interface is created automatically when the channel group gets its first physical
interface.
You do not have to disable the IP address that is assigned to a physical interface that is part of a channel
group, but we highly recommend that you do so.
You can create port channels by entering the interface port-channel global configuration command or
when the channel group gets its first physical interface assignment. The port channels are not created at
runtime or dynamically.
Any configuration or attribute changes you make to the port-channel interface are propagated to all
interfaces within the same channel group as the port channel (for example, configuration changes are
also propagated to the physical interfaces that are not part of the port channel, but are part of the channel
group).
With the on mode, a usable PAgP EtherChannel exists only when a port group in on mode is connected
to another port group in on mode.
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 interface to a channel group, and to use the interface
for transmission. Both ends of the link cannot be set to silent.
Note You cannot enable both PAgP and LACP modes on an EtherChannel group.
Caution You should exercise care when setting the mode to on (manual configuration). All ports configured in
the on mode are bundled in the same group and are forced to have similar characteristics. If the group is
misconfigured, packet loss or Spanning Tree Protocol (STP) loops might occur.
Release Modification
12.1(6)EA2 This command was first introduced. It replaced the port group command.
12.1(12c)EA1 The active and passive keywords were added.