Accounting pakets on layer 2

[Omri Bahumi]

Hi,

Usually, the same interface you're using for management is used for
sending accounting packets, just like SNMP management.
On Cisco IOS this is configurable with the "ip radius
source-interface" command. When unspecified, the gateway interface's
IP address
is being used instead.
Regarding "Which application is responsible for generating those
pakets?" - you'd have to consult the manual for that particular AP.

Good luck,
Omri.