Chapter 27
Configuring EtherChannel and Link State Tracking
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Configuring EtherChannel
These sections describe how to configure EtherChannel:
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Ensure that the interfaces are configured correctly. See the
Note
Restrictions" section on page
Configuring Layer 3 EtherChannels
To configure Layer 3 EtherChannels, create the port channel logical interface and then put the Ethernet
interfaces into the port channel.
Assign all interfaces in the EtherChannel to the same VLAN, or configure them as trunks.
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If you configure an EtherChannel from trunk interfaces, verify that the trunking mode and the
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native VLAN is the same on all the trunks. Interfaces in an EtherChannel with different trunk
modes or different native VLANs can have unexpected results.
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An EtherChannel supports the same allowed range of VLANs on all the interfaces in a trunking
Layer 2 EtherChannel. If the allowed ranges differ for selected interface differ, they do not form
an EtherChannel.
Interfaces with different Spanning Tree Protocol (STP) port path costs can form an
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EtherChannel as long they are otherwise compatibly configured. Setting different STP port path
costs does not make interfaces incompatible for the formation of an EtherChannel.
After you configure an EtherChannel, any configuration that you apply to the port channel interface
affects the EtherChannel; any configuration that you apply to the physical interfaces affects only the
interface you configure.
Storm Control is an exception to this rule. For example, you cannot configure Storm Control on
some of the members of an EtherChannel; Storm Control must be configured on all or none of the
ports. If you configure Storm Control on only some of the ports, those ports are dropped from the
EtherChannel interface (put in suspended state). You should configure Storm Control at the port
channel interface level, and not at the physical interface level.
A physical interface with port security enabled can join a Layer 2 EtherChannel only if port security
is also enabled on the EtherChannel; otherwise the command is rejected by the CLI.
You cannot configure a 802.1X port in an EtherChannel.
Configuring Layer 3 EtherChannels, page 27-7
Configuring Layer 2 EtherChannels, page 27-11
Configuring LACP Standalone or Independent Mode, page 27-13
Configuring LACP Port Channel Min-links, page 27-14
Configuring the LACP System Priority and System ID, page 27-16
Configuring EtherChannel Load Balancing, page 27-18
Removing an Interface from an EtherChannel, page 27-19
Removing an EtherChannel, page 27-20
27-6.
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Configuring EtherChannel
"EtherChannel Configuration Guidelines and
27-7