There are basically (5) five different types of Denial of Service attacks, the most primitive being the physical layer obviously which means I cut your CAT-6 cable, fiber line, etc denying and interrupting your service. Next you have exploit based denial of service attacks where a vulnerability exist that when a payload is sent crashes the service, Next you have one to one DoS attack which is basically useless these days if were talking bandwidth so we will use distributed denial of service attacks that focus on hacked servers or basically any networked device as individual nodes or bots that receive their attack commands from command and control servers and all the hosts at once attack. Another popular one used these days are layer 7 attacks which basically just send TCP SYN packets and when the server responds the TCP 3 way handshake is not completed therefore consuming all available sockets. We also have DrDoS attacks which utilize vulnerabilities in protocols to amplify attack bandwidth – if I issue a monlist command to an NTP server on port 123 that takes 5 bytes and I use the return target IP instead of my own to send the list to which is 500 bytes with thousands of bots I can create enough UDP bandwidth to deny service on a high scale. Listen more in my podcast below: