FortiWLC – Link Aggregation

Link Aggregation

Link aggregation allows data traffic across both Ethernet ports on AP resulting in increased throughput and redundancy. You can configure LACP only on the second interface of the AP. Before you configure LACP on the second interface of the AP, enable bonding on the switch that terminates AP. When configured for link aggregation, the second interface of the AP will inherit all properties of the first interface. When enabled, LACP is functional on both ports.

The second interface of the AP is disabled by default and when enabled it functions as the bonded pair to the first interface. The second interface cannot be used in standalone mode. However, when LACP is enabled and if one of the interfaces fails, the second interface takes over and passes traffic. During a failover, the second interface will function only if there is an external power supply or if the switch can provide only power via PoE.

Link aggregation is available only on AP832, AP822, FAP-U421, and FAP-U423. If the switch that terminates the AP does not support LACP, the AP will fall back to non-LACP mode with only one interface passing data traffic. Static bonding is not supported.


Before you enable LACP on the AP, ensure that you do the following

  • Remove port AP entry from the port profile of that AP.
  • Enable LACP support for the ports on the switch that terminates the AP.
  • AP requires 802.3at power to support LACP.

NOTE: If the switch does not support LACP, the AP will work in non-LACP mode.

Link Aggregation


Enabling LACP in CLI

Use the lacp enable command on an AP’s ethernet interface to enable LACP.

controller(15)# config terminal controller(15)(config)# interface ap 108 2 controller(15)(config‐if‐WiredEth)# lacp enable

Verifying LACP Status

The Uplink Type and LACP column in the show interfaces ap <ap-id> command displays the status of LACP for an AP.

Controller(15)# show interfaces Ethernet ap 108

Type        ID  Name            IfIndex MTU     MAC Address       Admin State Op State  Last Change          Uplink Type LACP     

ap          108 AP‐108          1       1500    00:0c:e6:13:01:a9 Up          Disabled  05/19/2014 20:05:12  Uplink      disable  

ap          108 AP‐108          2       1500    00:0c:e6:13:01:a9 Up          Disabled  05/20/2014 23:51:48  Uplink‐lacp enable   

        Ethernet Table(2 entries)

For additional diagnostics, you can view the Tx and Rx errors of AP interface using the show interfaces Ethernet statistics <ap-ID> command.

Controller(15)# show interfaces Ethernet statistics ap 13

 IfIndex   Node ID Node Name       Type        In Octets     In Errors     Out Octets    Out Errors   


  • 13 AP‐13           ap          78217745      0             4637677       0            
  • 13 AP‐13           ap          0             0             0             0            

LACP      13      AP‐13           ap          78217745      0             4638109       0            

        Ethernet Statistics(3 entries)

Enabling LACP in WebUI
  1. Goto Configuration > Devices > AP, select the AP.

Link Aggregation

  1. Goto Ethernet Interface tab, and select the second Ethernet Interface and set LACP to Enable.

To batch enable LACP on multiple APs.

  1. Goto Configuration > Wired > Ethernet, select all APs and click the Bulk Update button.
  2. Set LACP to Enable.

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