Sean was researching a new book on his home computer, when he noticed that his Internet connection was becoming slower and slower, until he had no Internet connection at all. He called his ISP to report the problem, and the ISP informed him that they were undergoing a DoS attack.

a. How does this sort of attack affect the ISP users?

b. What actions can the ISP take to mitigate the effects of this type of attack on its business?