> This informs us that for a PACKET_OUT with action OUTPUT, it cannot
> have its port as ANY. Now, I do not know why for a PACKET_OUT message,
> an action OUTPUT cannot have port as ANY. More importantly, I do not
> know why the controller seems to be sending the PACKET_OUT with action
> OUTPUT and port ANY.
A PACKET_OUT is usually a response to some message e.g. a PACKET_IN,
so it would probably help to see which message (if any) the switch
sent to the controller to receive that PACKET_OUT.