DDos
DDos isn't someone throwing bananas at your home, you can't defend against it by just closing a window and clean up the mess later.
This screen explains a little what DDos really is:
Doing DDos is incredible illegal as it's not only attacking and making some people unable to use internet (violating someones rights).
But it's also very serious in the subject spreading viruses.
To build a "Bot-Net", a network of Zombies, you need to get control over them using viruses and spread it.
It's not possible to defend yourself against DDos... the only defend you can do, is having power enough to not be completely effected by it.
No matter your firewall, the attacks are coming, it will block your internet not matter what magic words you use... (exura sio "modem)
There are services you could use that works like a proxy (internet tunnels) that's very powerful, and that filter the attacks from the real internet usage, and send the internet usage to you, and the attacks to themselves.
The real name of "DDos" is "
Distributed denial-of-service attack"
Dos
However, things you can protect yourself from is, is the one called "Dos" or in full name "
Denial of Service attack".
This kind of attack is that the attacker tell your computer, to send files to the attacker, for example images.
The incoming attack normally never passes 0,5 Mb/s in Dos, however the output from your computer could be as bad as 100 Mb/s.
Also the attacker use to spoof his IP address, make your computer try to send images, to an unvalid IP address, which in some cases cause your computer to attempt sending the image several times.
This is normally the one people misstake with DDos and say to OT owners "you fucking noob get some DDos protection" which doesn't work that way.
Dos protection is simple to get by using certain programs that will ignore such requests, so the computer can't send images like that.