From page 362 of the ArubaOS 8.4 user guide:
Striping LMS IP can no longer be used to stripe the traffic as each AP has GRE tunnels to more than one managed device. Therefore, starting from ArubaOS 8.2.0.0, Cluster LACP is used to stripe traffic on a per-UAC basis. That is, in a cluster setup, the clients or users on the same AP are steered to different UACs and the traffic is striped to these UACs.
When cluster is enabled, striping IP is not used even if it is a single-node cluster; the striping of traffic for the
Ethernet interfaces is according to the UAC node.
For a non-cluster setup, the striping LMS IP is used in the same way as before.
For an upstream traffic, the cluster LACP load-balances these UACs across the Ethernet ports.
For a downstream traffic, because the Source-IP and MAC address of the GRE packets are different from those of AP, the AP's uplink switch spreads the traffic.
To configure AP LACP using CLI:
On an uplink switch of an AP, use the following command to configure LACP between the two ethernet ports of the AP:
(host) [md] (config) #ap-lacp-striping-ip
(host) [md] (AP LACP LMS map information) #aplacp-enable
(host) [md] (AP LACP LMS map information) #striping-ip 10.15.127.2 lms 10.15.127.3
To view the configuration, execute the following command:
(host) #show ap-lacp-striping-ip
AP LACP LMS map information
---------------------------
Parameter Value
--------- -----
AP LACP Striping IP Enabled
GRE Striping IP 10.15.127.2 LMS 10.15.127.3
The lms-ip value in ap-system-profile will be used as a key to look up entries in ap-lacp profile.