User guide

4-4
Cisco WLAN Controller Web Interface User Guide
OL-7416-04
Chapter 4 Controller Menu Bar Selection
General
Link Aggregation
Link aggregation enables you to reduce the number of IP addresses needed to configure the ports on your
controller. This is achieved by grouping all the physical ports and creating a link aggregation group
(LAG). In a 4402 model, two ports are combined to form a LAG where as in a 4404 model, all four ports
are combined to form a LAG.
Note You cannot create more than one LAG on a controller.
Some of the advantages of creating a LAG are:
• If one of the links goes down, the traffic is moved to the other links in the LAG. Hence, as long as
one of the physical ports is working, the system remains functional.
• It eliminates the need to configure separate backup ports for each interface.
• Multiple AP-manager interfaces are not required since only one logical port is visible to the
application.
Note When you make changes to the LAG configuration, the controller has to be rebooted for the changes to
take effect.
When LAG is enabled on the controller, the following configuration changes occur:
• Any dynamic interfaces that you have created are deleted. This is done to prevent configuration
inconsistencies in the interface database.
• Interfaces cannot be created with the “Dynamic AP Manager” flag set.
Command Buttons
• Apply: Data is sent to the controller and made to take effect, but not preserved across a power cycle;
these parameters are stored temporarily in volatile RAM.