Symptom
The configuration guide does not explain what ARP broadcasts does.
Conditions
9800 ARP broadcast setting
Workaround
an opposite setting is to enable Proxy ARP in the policy profile which makes the WLC reply to ARP requests on behalf of the client (And then the client does not receive the ARP request at all anymore, which is hurtful in case of passive clients)
Further Problem Description
The WLC, in order to save air time, transforms ARP broadcast coming from the wired side and unicasts them to the wireless client it owns.
This is only possible once the WLC has learned the MAC-IP binding of its wireless client. Enabling ARP broadcast means the WLC will not transform ARP boadcasts into uni cast but will simply forward the broadcast, thus wasting airtime for other clients too (with a frame that is not acknowledgeable and therefore less reliable). This pushes the passive client to respond ro the ARP request and therefore every other client benefits from learning the MAC-IP binding of the wireless client.
