Are these keepalive sent from the AP to the AAC and waits for the AAC response? Or are they sent from the AAC to the AP and waits for the AP response? Or both?
The GRE keepalives are bi-directional.
And will the RAP reboostrap also after 8 keepalive misses as CAPs? I read somewhere RAPs will wait 30 seconds -
It is 8 seconds for CAPs and mesh portals, 30 for RAPs, 16 for mesh points. This can be configured ranging from 1 second to 60 seconds depending on the scenario.
However, since 8.5 GRE and ICMP keepalives are introduced.
Some information on how that works can be found in the post below
https://community.arubanetworks.com/t5/Controller-Based-WLANs/How-ICMP-keepalive-for-GRE-works/ta-p/657472
Since a RAP is in the picture, this may be configured to actively check the WAN connectivity as well.