Configuring The Lacp System Priority - Cisco ME 3400 Software Configuration Manual

Configuring EtherChannels
If you configure more than eight links for an EtherChannel group, the software automatically decides
which of the hot-standby ports to make active based on the LACP priority. The software assigns to every
link between systems that operate LACP a unique priority made up of these elements (in priority order):
•
•
•
•
In priority comparisons, numerically lower values have higher priority. The priority decides which ports
should be put in standby mode when there is a hardware limitation that prevents all compatible ports
from aggregating.
Ports are considered for active use in aggregation in link-priority order starting with the port attached to
the highest priority link. Each port is selected for active use if the preceding higher priority selections
can also be maintained. Otherwise, the port is selected for standby mode.
You can change the default values of the LACP system priority and the LACP port priority to affect how
the software selects active and standby links. For more information, see the
System Priority" section on page 34-20
page

Configuring the LACP System Priority

You can configure the system priority for all of the EtherChannels that are enabled for LACP by using
the lacp system-priority global configuration command. You cannot configure a system priority for
each LACP-configured channel. By changing this value from the default, you can affect how the software
selects active and standby links.
You can use the show etherchannel summary privileged EXEC command to see which ports are in the
hot-standby mode (denoted with an H port-state flag).
Beginning in privileged EXEC mode, follow these steps to configure the LACP system priority. This
procedure is optional.
Command
Step 1
configure terminal
Step 2
lacp system-priority priority
Step 3 end
Step 4 show running-config
or
show lacp sys-id
Step 5 copy running-config startup-config
To return the LACP system priority to the default value, use the no lacp system-priority global
configuration command.
Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
34-20
LACP system priority
System ID (a combination of the LACP system priority and the switch MAC address)
LACP port priority
Port number
34-21.
Chapter 34 Configuring EtherChannels and Link-State Tracking
and the "Configuring the LACP Port Priority" section on
Purpose
Enter global configuration mode.
Configure the LACP system priority.
For priority, the range is 1 to 65535. The default is 32768.
The lower the value, the higher the system priority.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
"Configuring the LACP
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