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Cisco Systems IntelligentGigabit Ethernet Switch Modules for the IBM BladeCenter, Software Configuration Guide
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Chapter24 Configuring EtherChann els and Layer 2 Trunk Failover
Configuring EtherChannels
•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 secure port as part of an EtherChannel or the reverse.
•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 con figuration from
the interfaces before globally enabling IEEE 802.1x on a sw itch by using the dot1x
system-auth-control global configuration command.
•An EtherChannel supports the same allowed range of VLANs on all the interfaces in a trunking
Layer 2 EtherChannel. When configuring an interface for PAgP, if the allowed range of VLANs is
not the same, the interfaces do not form an EtherChannel even when PAgP is set to the auto or
desirable mode. When configuring an interface for LACP, if the allowed range of VLANs is not the
same, the interfaces do not form an EtherChannel even when LACP is set to the active or passive
mode.
•Interfaces with different spanning-tree path cos ts can form an EtherChannel if they are otherwise
compatibly configured. Setting different spanning-tree path costs does not, by itself, make interfaces
incompatible for the formation of an EtherChannel.
Configuring Layer 2 EtherChannels
You configure Layer2 EtherChanne ls by configuring the Ethernet interfaces with the channel-group
interface configuration command, which creates the port-channel logical interfa ce. You cannot put a
Layer 2 interface into a manually created port-channel interface.
Note Layer 2 interfaces must be connected and functioning for the software to create port-channel interfaces.
Beginning in privileged EXEC mode, follow these steps to assign a Layer2 Ethernet interface to a
Layer 2 EtherChannel:
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Specify a physical interface to configure, and enter interface
configuration mode.
Valid interfaces include physical interfaces.
Up to eight interfaces of the same type and speed can be
configured for the same group.