Cisco Systems 2950, 2955 Default EtherChannel Configuration, EtherChannel Configuration Guidelines

30-8
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
OL-10101-02
Chapter 30 Configuring EtherChannels
Configuring EtherChannels
Default EtherChannel Configuration
Table 30-2 shows the default EtherChannel configuration.
EtherChannel Configuration Guidelines
If improperly configured, some EtherChannel ports 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 ports of the same type.
Note Do not configure a GigaStack GBIC port as part of an EtherChannel.
• Configure all ports in an EtherChannel to operate at the same speeds and duplex modes.
• Enable all interfaces 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 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
• 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 configuration from
the interfaces before globally enabling IEEE 802.1x on a switch by using the dot1x
system-auth-control global configuration command.
Tab l e 30-2 Default EtherChannel Configuration
Feature Default Setting
Channel groups None assigned.
PAgP mod e No default.
PAgP learn method Aggregate-port learning on all interfaces.
PAgP priority 128 on all interfaces. (Changing this value has no effect.)
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.