I was setting up my iptables with shorewall and as I was adding rules I wondered something. If I open a port, and any programs that use said port are not running, then what happens to the packets that someone might send to try to exploit that port? If no programs are up for the computer to send the packets to, then are they dropped? Logged? Something else?
All comments would be appreciated as I am trying to learn as much as possible, and I'm starting at a pretty low level.