Cisco IE 4000, Руководство по настройке программного обеспечения

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1028
Configuring EtherChannels
Information About Configuring EtherChannels
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:

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 put into an independent
state and continue 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.
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.
Port-Channel Interfaces
When you create an EtherChannel, a port-channel logical interface is involved:

With Layer 2 ports, use the channel-group interface configuration command to dynamically create the port-channel
logical interface.
You also can use the interface port-channel port-channel-number global configuration command to manually
create the port-channel logical interface, but then you must use the channel-group channel-group-number
command to bind the logical interface to a physical port. 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.

With Layer 3 ports, you should manually create the logical interface by using the interface port-channel global
configuration command followed by the no switchport interface configuration command. Then you manually assign
an interface to the EtherChannel by using the channel-group interface configuration command.
For both Layer 2 and Layer 3 ports, the channel-group command binds the physical port and the logical interface
together as shown in Figure 109 on page 1029 .
Each EtherChannel has a port-channel logical interface numbered from 1 to 10. This port-channel interface number
corresponds to the one specified with the
channel-group interface configuration command.