Cisco IE 4000, Software Configuration Manual

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1036
Configuring EtherChannels
Information About Configuring EtherChannels

Do not try to configure more than 6 EtherChannels on the switch.

Configure a PAgP EtherChannel with up to ten Ethernet ports of the same type.

Configure a LACP EtherChannel with up to16 Ethernet ports of the same type. Up to eight ports can be active, and
up to eight ports can be in standby mode.

Configure all ports in an EtherChannel to operate at the same speeds and duplex modes.

Enable all ports in an EtherChannel. A port in an EtherChannel that is disabled by using the shutdown interface
configuration command is treated as a link failure, and its traffic is transferred to one of the remaining ports in the
EtherChannel.

When a group is first created, all ports follow the parameters set for the first port to be added to the group. If you
change the configuration of one of these parameters, you must also make the changes to all ports in the group:
— Allowed-VLAN list
— Spanning-tree path cost for each VLAN
— Spanning-tree port priority for each VLAN
— Spanning-tree Port Fast setting

Do not configure a port to be a member of more than one EtherChannel group.

Do not configure an EtherChannel in both the PAgP and LACP modes. EtherChannel groups running PAgP and LACP
can coexist on the same switch. Individual EtherChannel groups can run either PAgP or LACP, but they cannot
interoperate.

Do not configure a Switched Port Analyzer (SPAN) destination port as part of an EtherChannel.

Do not configure a secure port as part of an EtherChannel or the reverse.

Do not configure a private-VLAN port as part of an EtherChannel.

Do not configure a port that is an active or a not-yet-active member of an EtherChannel as an IEEE 802.1x port. If
you try to enable IEEE 802.1x on an EtherChannel port, an error message appears, and IEEE 802.1x is not enabled.

If EtherChannels are configured on switch interfaces, remove the EtherChannel configuration from the interfaces
before globally enabling IEEE 802.1x on a switch by using the
dot1x system-auth-control global configuration
command.

For Layer 2 EtherChannels:
— Assign all ports in the EtherChannel to the same VLAN, or configure them as trunks. Ports with different native
VLANs cannot form an EtherChannel.
— If you configure an EtherChannel from trunk ports, verify that the trunking mode (ISL or IEEE 802.1Q) is the same
on all the trunks. Inconsistent trunk modes on EtherChannel ports can have unexpected results.
— An EtherChannel supports the same allowed range of VLANs on all the ports in a trunking Layer 2 EtherChannel.
If the allowed range of VLANs is not the same, the ports do not form an EtherChannel even when PAgP is set to
the
auto or desirable mode.
— Ports with different spanning-tree path costs can form an EtherChannel if they are otherwise compatibly
configured. Setting different spanning-tree path costs does not, by itself, make ports incompatible for the
formation of an EtherChannel.