Configuring Etherchannels - Cisco 3032 Software Configuration Manual

Configuring EtherChannels

With PAgP, if the stack master fails or leaves the stack, a new stack master is elected. A spanning-tree
reconvergence is not triggered unless there is a change in the EtherChannel bandwidth. The new stack
master synchronizes the configuration of the stack members to that of the stack master. The PAgP
configuration is not affected after a stack master change unless the EtherChannel has ports residing on
the old stack master.
With LACP, the system-id uses the stack MAC address from the stack master, and if the stack master
changes, the LACP system-id can change. If the LACP system-id changes, the entire EtherChannel will
flap, and there will be an STP reconvergence. Use the stack-mac persistent timer command to control
whether or not the stack MAC address changes during a master failover.
For more information about switch stacks, see
Configuring EtherChannels
These sections contain this configuration information:
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Note Make sure that the ports are correctly configured. For more information, see the
Configuration Guidelines" section on page
Note After you configure an EtherChannel, configuration changes applied to the port-channel interface apply
to all the physical ports assigned to the port-channel interface, and configuration changes applied to the
physical port affect only the port where you apply the configuration.
Default EtherChannel Configuration
Table 37-3
Table 37-3
Feature
Channel groups
Port-channel logical interface
PAgP mode
PAgP learn method
PAgP priority
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
37-10
Default EtherChannel Configuration, page 37-10
EtherChannel Configuration Guidelines, page 37-11
Configuring Layer 2 EtherChannels, page 37-12
Configuring Layer 3 EtherChannels, page 37-14
Configuring EtherChannel Load-Balancing, page 37-17
Configuring the PAgP Learn Method and Priority, page 37-18
Configuring LACP Hot-Standby Ports, page 37-19
shows the default EtherChannel configuration.
Default EtherChannel Configuration
Chapter 37 Configuring EtherChannels and Link-State Tracking
Chapter 5, "Managing Switch Stacks."
(required)
(required)
(optional)
(optional)
(optional)
37-11.
Default Setting
None assigned.
None defined.
No default.
Aggregate-port learning on all ports.
128 on all ports.
"EtherChannel
OL-12247-04