The best defense is to unplug your Ethernet cable. No more internet = no more attacks. Problem solved. You're welcome.
Originally Posted by GiveMeLibertyOrGiveMeHead
But if on dial-up, the phone line.
Seriously, concern over a home line? No one that is capable of a ddos attack would even be remotely interested in a home line.
Besides let your kid play games at his age. Actual sports might be preferred, but there's a nice paycheck in computer software and tech systems management nowadays. And that starts with just getting used to the tech and other software with hands on time, even if just games.