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30-8
Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 30 Configuring EtherChannels
Configuring EtherChannels
Default EtherChannel Configuration
shows the default EtherChannel configuration.
EtherChannel Configuration Guidelines
If improperly configured, some EtherChannel interfaces are automatically disabled to avoid network
loops and other problems. Follow these guidelines to avoid configuration problems:
•
Configure an EtherChannel with up to eight Ethernet interfaces of the same type.
Note
Do not configure a GigaStack GBIC port as part of an EtherChannel.
•
Configure all interfaces in an EtherChannel to operate at the same speeds and duplex modes.
•
Enable all interfaces in an EtherChannel. An interface 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 interfaces 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
•
An EtherChannel interface that is configured as a Switched Port Analyzer (SPAN) destination port
does not join the group until it is deconfigured as a SPAN destination port.
•
Do not configure a secure port as part of an EtherChannel.
Table 30-2 Default EtherChannel Configuration
Feature
Default Setting
Channel groups
None assigned.
Layer 3 port-channel logical interface
None defined.
PAgP mode
No default.
PAgP learn method
Aggregate-port learning on all interfaces.
PAgP priority
128 on all interfaces.
LACP learn method
Aggregate-port learning on all interfaces.
LACP priority
32768 on all interfaces.
Load balancing
Load distribution on the switch is based on the
source-MAC address of the incoming packet. Load
distribution based on the source and destination IP
address is also enabled for routed IP traffic.