so how do I know if I get hacked? [smc barricade router] [aol]

Q Ive got a SMC Barricade router and I was reading the reports
it has a number of unauthorized access from certain IPs and port # 0.
typically port # 80 that is accessed and 27374
Now how do I know that someone is trying to make my computer open?
could of AOL? or some other applications?
neither received permission from the ports in the config page, so how do they access that?

thanks