DDOS Computer IP Address/Default Gateway IP Address.

Hello guys, How are you?

Uhm.. Is there a way to ddos my friend's internet? so it become slow or something? not his computer, his internet.

I searched internet and all I've found is about how to ddos/dos a website..

and I dont want to dos a website..

if it doesnt matter if it was a website or internet ip address, just tell me the way to do it.. I want to know make it effective...

Thanks in forward :)