05 - Denial of Service

 1. A Denial-of-Service (DoS) attack is an attack meant to shut down a machine or network, making it inaccessible to its intended users.



 2. An attack like this occurs when multiple systems flood the bandwidth of a targeted system, usually one or more _________.

  web servers

  website html pages

  individuals (humans)

  client machines

 3. Panix, the third-oldest ISP in the world, was the target of what is thought to be the first DoS attack. This was in the year 1996.



 4. In a distributed denial-of-service attack (DDoS attack), the incoming traffic flooding the victim originates from _________.

  a single source.

  many different sources.

  only two sources, each in the same location.

  a human and not a computer.

 5. The above scenario effectively makes it impossible to stop the attack simply by ______________________.

  visiting people's homes.

  blocking a single source.

  blocking the ISPs packet switching network.

  asking for permission.

 6. Criminal perpetrators of DoS attacks often target sites or services hosted on high-profile web servers such as banks or credit card payment gateways.



 7. Revenge, blackmail and activism is never likely to be the reason behind any of these attacks.



 8. A _________________ attack typically involves more than around 3?5 nodes on different networks; fewer nodes may qualify as a DoS attack but is not a DDoS attack.

  disinfected serial

  distributed denial of service

  disintegrated systems

  denegrated service

 9. The simplest DoS attack relies primarily on ________, flooding the target with an overwhelming flux of packets, depleting the target's system resources.

  vulnerabilities in government security

  sql injections

   brute force

  careful physical intervention on the client side

 10. A SYN flood occurs when a host sends a flood of__________________ often with a forged sender address.

  TCP/IP procotols

  physical letters in the post

  MAC addresses

   TCP/SYN packets,