Question 2 (20 marks, 5 marks each) Explain how would use a firewall (and what category) for each of the following scenarios. You need to justify your selection:

a) A bookstore lists the books on sale through its website. We do not want any client to launch a SQL injection or XSS/XSRF attack when they attempt to access the website.

b) An organization wants to give remote login access for its employers to their office computer. The office computers could differ in the operating system employed and do not have a strong authentication mechanism.

c) A user wants to prevent an XSRF attack to be launched when he opens an email on his PC.

d) A network administrator wants to restrict clients from downloading beyond a certain number of bytes from a file server over a time period.

e) Auditing a network security attack (i.e., trace the sequence of packets that have entered and/or left an organizations network)